Buckling foam cushioning devices

ABSTRACT

Various cushioning devices, materials for making cushioning elements, and manufacturing techniques for cushioning elements are disclosed.

PRIORITY

[0001] This patent application is a divisional of U.S. patentapplication Ser. No. 10/059,101 filed on Nov. 8, 2001, now ______, whichis a continuation-in-part of U.S. patent application Ser. No. 09/303,919filed May 3, 1999, now U.S. Pat. No. 6,413,458, which is acontinuation-in-part of U.S. patent application Ser. No. 08/968,750filed on Aug. 13, 1997, now U.S. Pat. No. 6,026,527, which is acontinuation-in-part of U.S. patent application Ser. No. 08/601,374filed on Feb. 14, 1996, now U.S. Pat. No. 5,749,111, which is acontinuation-in-part of U.S. patent application Ser. No. 08/783,413filed on Jan. 10, 1997, now U.S. Pat. No. 5,994,450 and priority to andbenefit of each of the foregoing is claimed. This patent application isalso a divisional of U.S. patent application Ser. No. 10/059,101 filedon Nov. 8, 2001, now ______, which is a continuation-in-part of U.S.patent application Ser. No. 09/932,393 field on Aug. 17, 2001, now______, which is a continuation-in-part of U.S. patent application Ser.No. 09/303,979 filed on May 3, 1999, now U.S. Pat. No. 6,413,458, whichclaims benefit of U.S. Provisional Patent Application Ser. No.60/226,726 filed on Aug. 18, 2000, and priority to and benefit of eachof the foregoing is claimed.

BACKGROUND

[0002] This subject matter herein invention relates to the field ofcushioning devices, gelatinous elastomers and devices made therefrom.More particularly, some embodiments relate to a cushion or cushioningdevice made in whole or in part of gelatinous elastomer, gelatinousvisco elastomer, and the elastomers themselves, methods for making anyof the foregoing, and structures made from the foregoing and othercushioning structures and other devices including gelatinous elastomers.

SUMMARY

[0003] Various cushioning devices and materials are disclosed.

BRIEF DESCRIPTION OF THE DRAWINGS

[0004]FIG. 1 depicts one embodiment of the cushion as part of an officechair.

[0005]FIG. 2 depicts one embodiment of the cushion including itscushioning element and cover.

[0006]FIG. 3 depicts a cutaway of one embodiment of the cushion of FIG.1 at 3-3.

[0007]FIG. 4 depicts a mold which may be used to manufacture oneembodiment of the cushion.

[0008]FIG. 5 depicts an alternative mold for manufacturing oneembodiment of the cushion.

[0009]FIG. 6 depicts a cross sectional view of a cushion manufacturedusing the mold of FIG. 5.

[0010]FIG. 7 depicts an isometric view of an alternative embodiment ofthe cushion.

[0011]FIG. 8 depicts a top view of an alternative embodiment of thecushion.

[0012]FIG. 9 depicts an isometric view of an alternative embodiment ofthe cushion.

[0013]FIG. 10 depicts a top view of an alternative embodiment of thecushion.

[0014]FIG. 11 depicts a cross sectional view of a column of an examplecushion during buckling.

[0015]FIG. 12 depicts a cross sectional view of a column of an examplecushion during another mode of buckling.

[0016]FIG. 13 depicts forces in play as an example cushion buckles.

[0017]FIG. 14 depicts an alternative structure for a column and itswalls.

[0018]FIG. 15 depicts a. cross section of a cushion using alternatingstepped columns.

[0019]FIG. 16 depicts am alternative embodiment of the cushioningelement having gas bubbles within the cushioning media.

[0020]FIG. 17 depicts an example cushion in use with a combination baseand container.

[0021]FIG. 18 depicts an example cushion having side wall reinforcementsto support the cushioning element.

[0022]FIG. 19 depicts an example cushioning element having a girdle orstrap about its periphery to support the cushioning element.

[0023]FIG. 20 depicts an example cushioning element with closed columntops and bottoms and fluid or other cushioning media contained withinthe column interiors.

[0024]FIG. 21 depicts an example cushioning element with firmnessprotrusions placed within the column interiors.

[0025]FIG. 22 is a frontal perspective view of an embodiment of thecushioning element which include multiple individual cushioning units.

[0026]FIG. 23a is a frontal perspective view of an embodiment of thecushioning element in which a first cushioning medium is containedwithin a second cushioning medium.

[0027]FIG. 23b is a cross section taken along line 23 b-23 b of FIG.23a.

[0028]FIG. 23c is a frontal perspective view of an alternateconfiguration of the embodiment shown in FIG. 23a.

[0029]FIG. 23d is a cross section taken along line 23 d-23 d of FIG.23c.

[0030]FIG. 24a is a frontal perspective view of an embodiment of thecushioning element in which the! outer surfaces of the cushioning mediumare covered with a coating.

[0031]FIG. 24b is a cross section taken along line 24 b-24 b of FIG.24a.

[0032]FIG. 25a is a perspective view of an embodiment of the cushioningelement, wherein the cushion includes multiple sets of parallel columnsand wherein each column intersects no columns of another parallel columnset or columns of only one other set.

[0033]FIG. 25b is a cross section taken along line 25 b-25 b of FIG.25a.

[0034]FIG. 25c is a cross section taken along line 25 c-25 c of FIG.25a.

[0035]FIG. 25d is a perspective view of an alternative configuration ofthe embodiment shown in FIG. 25a, wherein each column may intersectcolumns of any number of the other parallel column sets.

[0036]FIG. 25e is a cross section taken along line 25 e-25 e of FIG.25d.

[0037]FIG. 25f is a cross section taken along line 25 f-25 f of FIG.25d.

[0038]FIG. 26 is a frontal perspective view of an embodiment of thecushioning element wherein the cushion has multiple sets of parallelnarrow columns.

[0039]FIG. 27a is a frontal perspective view of an embodiment of thecushioning element which includes multiple sets of parallel columns andcavities formed in the column walls.

[0040]FIG. 27b is a cross section taken along line 27 b-27 b of FIG.27a.

[0041]FIG. 27c is a cross section taken along line 27 c-27 c of FIG.27a.

[0042]FIG. 28 is a frontal perspective view of an embodiment of thecushioning element which has a contoured surface and includes columns ofmore than one height.

[0043]FIG. 29 is a frontal perspective view of an embodiment of thecushioning element wherein the cushioning medium is foamed.

[0044]FIG. 30a is a frontal perspective view of an embodiment of thecushioning element wherein the column walls are formed from numerousshort tubular pieces, which create voids in the column walls.

[0045]FIG. 30b is a frontal perspective view of an alternativeconfiguration of the cushioning element shown in FIG. 30a, wherein thecolumn walls include voids created by extracting space consuming objectstherefrom following molding of the cushioning medium.

[0046]FIG. 31a depicts a carbon atom and its covalent bonding sites.

[0047]FIG. 31b depicts a hydrogen atom and its covalent bonding site.

[0048]FIG. 31c depicts a four carbon hydrocarbon molecule known asbutane.

[0049]FIG. 32a depicts a triblock copolymer useful in a cushioningmedium.

[0050]FIG. 32b depicts the triblock copolymer of FIG. 32a in a relaxedstate.

[0051]FIG. 33a depicts the chemical structure of a styrene molecule.

[0052]FIG. 33b depicts the chemical structure of a benzene molecule.

[0053]FIG. 33c depicts the chemical structure of an aryl group.

[0054]FIG. 33d depicts, the chemical structure of an-enyl group.

[0055]FIG. 33e depicts the chemical structure of an ethenyl group.

[0056]FIG. 33f depicts the chemical structure of a propenyl group.

[0057]FIG. 34a depicts a midblock (B) of the triblock copolymer of FIG.32a.

[0058]FIG. 34b depicts an endblock (A) of the triblock copolymer of FIG.32a.

[0059]FIG. 34c depicts the weak bonding between the monomer unites ofone or more midblocks (B) of the triblock copolymer of FIG. 32a.

[0060]FIG. 34d depicts an endblock (A) of the triblock copolymer of FIG.32a, showing the endblock (A) in a relaxed state.

[0061]FIG. 35a depicts the chemical structure of hydrocarbon moleculesknown as alkanes.

[0062]FIG. 35b depicts the chemical structure of hydrocarbon moleculesknown as alkenes.

[0063]FIG. 35c depicts the chemical structure of hydrocarbon moleculesknown as alkynes.

[0064]FIG. 35d depicts the chemical structure of a hydrocarbon moleculeknown as a conjugated diene.

[0065]FIG. 35e depicts the chemical structure of a hydrocarbon moleculeknown as an isolated diene.

[0066]FIG. 36a depicts the chemical structure of apoly(ethylene/butylene) molecule.

[0067]FIG. 36b depicts the chemical structure of apoly(ethylene/propylene) molecule.

[0068]FIG. 36c depicts the chemical structure of a 1,3-butadienemolecule.

[0069]FIG. 36d depicts the chemical structure of an isoprene molecule.

[0070]FIG. 37a depicts polystyrene-poly(ethylene/butylene)-polystyrene.

[0071]FIG. 37b depicts polystyrene-poly(ethylene/propylene)-polystyrene.

[0072]FIG. 37c depicts polystyrene-polybutadiene-polystyrene.

[0073]FIG. 37d depicts polystyrene-polyisoprene-polystyrene.

[0074]FIG. 37e depicts polystyrene-poly(isoprene+butadiene)-polystyrene.

[0075]FIG. 37f depicts polystyrene-poly(ethylene/butylene+ethylene/propylene)-polystyrene.

[0076]FIG. 38a depicts the chemical structure ofpolystyrene-poly(ethylene/butylene+ethylene/propylene)-polystyrene.

[0077]FIG. 38b depicts the group of the triblock copolymers of FIG.321a, showing weak attraction of the endblocks to each other.

[0078]FIG. 39a illustrates plasticizer association with the group oftriblock copolymers of FIG. 38b.

[0079]FIG. 39b illustrates the lubricity theory of plasticization,showing two midblocks (B) moving away from each other.

[0080]FIG. 39c illustrates the lubricity theory of plasticization,showing two midblocks (B) moving toward each other.

[0081]FIG. 39d illustrates the lubricity theory of plasticization,showing two midblocks (B) moving across each other.

[0082]FIG. 39e illustrates the gel theory of plasticization, showing aweak attraction between two midblocks (B) when plasticizer is notpresent.

[0083]FIG. 39f illustrates the gel theory of plasticization, showing aplasticizer molecule breaking the weak attraction of FIG. 39e.

[0084]FIG. 39g illustrates the mechanistic theory of plasticization,showing an equilibrium of plasticizer breaking the weak attraction ofmidblocks (B) for each other.

[0085]FIG. 39h illustrates the free volume theory of plasticization,showing the free space associated with a midblock (B).

[0086]FIG. 39i illustrates the theory of FIG. 39h, showing that as smallplasticizer molecules are added, the free space in a given areaincreases.

[0087]FIG. 39j illustrates the theory of FIG. 39h, showing the evensmall plasticizers provide an even greater amount of free space.

[0088]FIG. 40a depicts the use of an extruder to perform a method forfoaming gel cushioning media.

[0089]FIG. 40b depicts the use of an injection molding machine toperform a method for foaming a gel cushioning media.

[0090]FIG. 41 depicts an embodiment of a cushioning element, wherein aplurality of tubes are bonded together to form the cushion.

[0091]FIG. 42 depicts a method for bonding the individual tubes of FIG.41 together to form the cushioning element shown therein.

[0092]FIG. 43 depicts cut foam bun of step 1.

[0093]FIG. 44 depicts cut foam bun of step 2.

[0094]FIG. 45 depicts cut foam bun of step 3.

[0095]FIG. 46 depicts bonded foam of step 4.

[0096]FIG. 47 depicts insertion of side support pieces of step 5.

[0097]FIG. 48 depicts top view of bottom core piece.

[0098]FIG. 51 depicts cut foam bun of step 1.

[0099]FIG. 52a depicts separated foam of step 2.

[0100]FIG. 52b depicts aligned foam of step 3.

[0101]FIG. 53 depicts bonded foam of step 4.

[0102]FIG. 54 depicts compressed foam rail.

[0103]FIG. 55 depicts foam and gellycomb cross-section.

[0104]FIG. 56 depicts foam and gellycomb with pillow-top layer incross-section.

[0105]FIG. 57 depicts foam and gellycomb with two pillow-top layers incross-section.

[0106]FIG. 58 depicts foam and gellycomb cross-section.

[0107]FIG. 59 depicts foam and gellycomb with gellycomb comfort layercross-section.

[0108]FIG. 60a depicts side view with foam inserted.

[0109]FIG. 60b depicts side view of foam construction.

[0110]FIG. 60c depicts front view of foam construction.

[0111]FIG. 61 depicts foam insertion of step 1.

[0112]FIG. 62 depicts a cut-away view of foam.

[0113]FIG. 63 depicts gellycomb pillow-top layer.

[0114]FIG. 64 depicts gellycomb pillow-top layer with two layers.

[0115]FIG. 65 depicts foam construction.

[0116]FIG. 66 depicts foam construction.

[0117]FIG. 67a depicts the no tool assembly.

[0118]FIG. 67b depicts the no tool assembly of step 1.

[0119]FIG. 67c depicts folded down sides of step 2.

[0120]FIG. 67d depicts snapped corners of step 3.

[0121]FIG. 67e depicts loam construction.

[0122]FIG. 68a depicts flat construction.

[0123]FIG. 68b depicts folded down construction.

[0124]FIG. 69a depicts top view.

[0125]FIG. 69b depicts front view.

[0126]FIG. 69c depicts end view.

[0127]FIG. 70 depicts quilted top with fiber and gel elastomer layer.

[0128]FIG. 71 depicts quilted top with fiber and two gel elastomerlayers.

[0129]FIG. 72 depicts quilted top with fiber and foam and thicker gelelastomer layer.

[0130]FIG. 73 depicts quilted top with fiber and one thin gel elastomerlayer and one thick gel elastomer layer.

[0131]FIG. 74 depicts quilted top with fiber, two thin gel elastomerlayers and one thick gel elastorrier layer.

[0132]FIG. 75 depicts quilted top with fiber, one thin gel elastomerlayer, and polyurethane foam.

[0133]FIG. 76 depicts quilted top with fiber, two thin gel elastomerlayers, and polyurethane

[0134]FIG. 77 depicts quilted top with fiber, one thin gel elastomerlayer, and high-grade visco-foam.

[0135]FIG. 78 depicts quilted top with fiber, one thin gel elastomerlayer, and spring unit.

[0136]FIG. 79 depicts quilted top with fiber, two thin gel elastomerlayers, and spring unit.

[0137]FIG. 80 depicts quilted top with fiber and foam, thick gelelastomer layer, and spring unit

[0138]FIG. 81 depicts quilted top with fiber, thin gel elastomer layer,and latex foam.

[0139]FIG. 82 depicts quilted top with fiber, latex topper, and thickgel elastomer layer.

[0140]FIG. 83 depicts quilted top with fiber, latex foam, and thick gelelastomer layer.

[0141]FIG. 84 depicts quilted top with fiber, polyurethane foam, andthick gel elastomer layer.

[0142]FIG. 85 depicts quilted top with fiber, pillow-soft polyurethanefoam, and thick gel elastomer.

[0143]FIG. 86 depicts inserted molten material.

[0144]FIG. 87 depicts pearlized chintz quilt with foam and fiber;Intellifoam; and

[0145] non-skid fabric.

[0146]FIG. 88 depicts pearlized chintz pillow-top with foam convolutedfoam and fiber; Intelli-foam; and non-skid fabric.

[0147]FIG. 89 depicts Belgian damask quilt with foam and fiber;SuperSoft latex; Intellifoam; and Belgian damask tick.

[0148]FIG. 90 depicts Belgian damask quilt with foam and fiber;SuperSoft Latex; Intellifoam; Firmsoft; and Belgian damask tick.

[0149]FIG. 91 depicts Belgian damask quilt with Supersoft fiber;SuperSoft latex; IntelLatex; Intelli-loam; and Belgian damask tick.

[0150]FIG. 92 depicts Belgian damask quilt with foam and fiber;Intelli-Gel; and Belgian damask: tick.

[0151]FIG. 93 depicts Belgian damask quilt with foam and fiber;Intelli-foam; Intelli-Gel; and Belgian Damask Tick.

[0152]FIG. 94 depicts pearlized chintz quilt with foam and fiber;Intelli-foam; springs; and non-skid fabric.

[0153]FIG. 95 depicts Belgian damask quilt with Supersoft fiber;IntelLatex; springs; and Belgian Damask tick.

[0154]FIG. 96 depicts stretch knit cover; Memory-foam; and Intelli-foam.

[0155]FIG. 97 depicts stretch knit cover; SuperSoft latex; andIntelLatex.

DETAILED DESCRIPTION

[0156] A. Configuration of the Cushions

[0157]FIG. 1 depicts a cushioned object 101, in this instance a humanbeing, atop of a piece of furniture 102, in this instance a chair, whichincludes the cushion 103. Although in this embodiment, the cushion 103is depicted as part of an office chair, the cushion may be used withmany types of products, including furniture such as sofas, love seats,kitchen chairs, mattresses, lawn furniture, automobile seats, theatreseats, padding found beneath carpet, padded walls for isolation rooms,padding for exercise equipment, wheelchair cushions, bed mattresses, andothers.

[0158] Referring to FIG. 2, the cushion 103 of FIG. 1 is depicted ingreater detail. The cushion 103 includes a cover 204. An example coveris a durable and attractive fabric, such as nylon, cotton, fleece,synthetic polyester or another suitable material which may bestretchable and elastic and which readily permits the flow of airthrough it to enhance ventilation of a cushioned object. Within thecover 204, a cushioning element 205 is to be found. As can be seen fromFIG. 2, the cushioning element 205 comprises a cushioning media of adesired shape. In the embodiment depicted, the cushioning element 205includes gel cushioning media formed generally into a rectangle withfour sides, a top and a bottom, with the top and bottom being orientedtoward the top and bottom of the page, respectively. The cushioningelement has within its structure a plurality of hollow columns 206. Asdepicted, the hollow columns 206 contain only air. The hollow columns206 are open to the atmosphere and therefore readily permit aircirculation through them, through the cover 204 fabric, and to thecushioned object. The columns 206 have column walls 207 which in theembodiment depicted are hexagonal in configuration. The total volume ofthe cushioning element may be occupied by not more than about 50% gelcushioning media, and that the rest of the volume of the cushioningelement will be gas or air. The total volume of the cushioning elementmay be occupied by as little as about 9% cushioning media, and the restof the volume of the cushion will be gas or air. This yields alightweight cushion with a low overall rate of thermal transfer and alaw overall thermal mass. It is not necessary that this percentage becomplied with in every instance.

[0159] Referring to FIG. 3, a cushioned object 101, in this instance ahuman being, is depicted being cushioned by the cushion 103 whichincludes cushioning element 205 within cover 204. Also visible is acushion base 301 of a rigid material such as wood, metal, plastic onwhich the cushioning element 205 rests. The cushioning element 206includes hollow columns 206 with walls 207. It can be seen that beneaththe most protruding portion of the cushioned object, in this instance ahip bone 302, the hollow columns 303 have walls 304 which have partiallyor completely buckled in order to accommodate the protuberance 302 andavoid creating a high pressure point below the protuberance 302 inresponse to the compressive force exerted by the cushioned object.Buckled columns offer little resistance to deformation, thus removingpressure from the hip bone; area. It can also be seen that in portionsof the cushioning element 205 which are not under the protuberance 302,the cushioning media which forms the walls 304 of the hollow columns 303has compressed but the columns 303 have not buckled, thus loading thecushioned object across the broad surface area of its non-protrudingportions. The cushion is yieldable as a result of the compressibility ofthe cushioning media and the bucklability of the columns (or columnwalls). The cushion 103 is depicted as having been manufactured usingthe mold depicted in FIG. 4. It can be seen from this cushion's responseto a compressive force exerted by the cushioned object that the cushionand the cushioning element are adapted to have a cushioned object placedon top of them.

[0160] Referring to FIG. 6, a cross section of an alternative embodimentis depicted. The cushioning element 601 includes cushioning media 604(which may be a gel cushioning media) which form walls 605 for columns602, 603. It can be seen that the columns 602 and 603 are oriented intoa group protruding from the top of the cushioning element 601 down intothe cushioning media 604 but not reaching the bottom of the cushioningelement of which column 602 is a member, and a group protruding from thebottom of the cushioning element 601 into the cushioning element 601 butnot reaching the top of the cushioning element 601 of which column 602is a member. This yields a generally firmer cushion than that shown insome other figures. This cushion would be manufactured by the molddepicted in FIG. 5.

[0161] Referring to FIG. 7, an alternative embodiment of a cushioningelement 701 is depicted. The cushioning element includes cushioningmedia 702, columns 703 and column walls 704. The columns depicted inFIG. 7 are square in a cross section taken orthogonal to theirlongitudinal axis, in contrast to the columns of FIG. 2 which arehexagonal in a cross section taken orthogonal to their longitudinalaxis. It is also of note that in FIG. 7, the columns 703 are arranged asan n×m matrix with each row and each column of columns in the matrixbeing aligned perfectly adjacent to its neighbor, with no offsetting.Exemplary sizing and spacing of columns would include columns which havea cross sectional diameter taken Referring to FIG. 8, a top view of analternative cushioning element 801 is depicted. The cushioning element801 includes cushioning media 802 which forms column walls 804, columns803 and an exterior cushioning element periphery 805. It can be seenthat the columns 803 of FIG. 8 are arranged in offset fashion withrespect to some of the columns to which they are adjacent. A myriad ofcolumn arrangements are possible, from well-organized arrangements ofthe columns to a random columnar arrangement. The columns may bearranged so that the total volume of gel cushioning media 802 within thevolume of space occupied by the cushioning element 801 is minimized.This results in a lightweight cushion. To that end, the columns 803 maybe arranged in close proximity to each other in order to minimize thethickness of the column walls 804. This will result in a lighter cushionand a cushion that will yield to a greater extent under a cushionedobject of a given weight than a similar cushion with thicker columnwalls 804.

[0162] Referring to FIG. 9, an alternative cushioning element 901 isdepicted with cushioning media 902, columns 903, column walls 904 andouter periphery 905 of the cushioning element 901 being shown. Thecolumns 902 depicted are round in a cross section taken orthogonal totheir longitudinal axes. The reader should note that it may be desirableto include a container or side walls which will contain the outerperiphery 905 of the cushioning element. For example, in FIG. 9, arectangular box with interior dimensions just slightly larger than theexterior dimensions of the cushioning element 901 could be employed. Or,as shown in FIG. 1, the side walls of the cover 204 could be rigid, suchas by the use of plastic inserts. The effect of rigid side walls or arigid container for a cushioning element is that when a cushioned objectis placed on the cushioning element, the cushioning media will not bepermitted to bulge outward at the cushioning element outer periphery. Bypreventing such outward bulging, greater cushion stability is achievedand a more direct (i.e. in a direction parallel to the longitudinal axisof a column, which in most of the figures, such as FIG. 3, is assumed tobe in the direction of the Earth's gravity but which may not always beso) movement or descent of the cushioned object into the cushion isachieved. A direct movement or descent of a cushioned object into thecushion (i.e. parallel to the longitudinal axes of the columns) isdesired because the column walls are configured to absorb weight andcushion the cushioned object, or, if the load under a protuberance getshigh enough, by buckling of the columns. If a cushioned object travels asubstantial distance sideways in the cushion, the hollow portion of thecolumns may be eliminated by opposing column walls collapsing to meeteach other rather than either substantially compressing the cushioningmedia or by buckling as depicted in FIGS. 13 and 14. This would notprovide the desired cushioning effect as it would result in collapsedcolumns within the cushion (rather than buckled columns), and thecushion would have little more cushioning effect than a solid block ofthe cushioning media without the columns.

[0163] Referring to FIG. 10, an alternative embodiment of the cushion1001 is depicted. The cushion 1001 includes gel cushioning media 1002 inthe form of an outer cushion periphery 1003, and column walls 1004 whichform triangular hollow columns 1005. The reader should note that thecolumns of the various figures are merely illustrative, and in practice,the columns could be triangular, rectangular, square, pentagonal,hexagonal, heptagonal, octagonal, round, oval; n-sided or any othershape in a cross section taken orthogonal to the longitudinal axis of acolumn. The periphery of the cushioning element may also be triangular,rectangular, square, pentagonal, hexagonal, heptagonal, octagonal,round, oval, heart-shaped, kidney-shaped, elliptical, oval, egg-shaped,n-sided or any other shape.

[0164]FIG. 11 depicts a column 1101 including column walls 1102 and 1103and column interior 1104. The column 1101 has a longitudinal axis 1105which can be oriented in the cushion parallel to the direction of thelongitudinal axis of a column which should be the direction that thecushioned object sinks into the cushion. Thus, the column top 1106 is atthe side of the cushion that contacts the cushioned object, and thecolumn bottom 1107 is at the side of the cushion that typically facesthe ground and will rest on some sort of a base. Another way ofdescribing this with respect to the longitudinal axis of each column isthat the column top is at one end of the longitudinal axis of a columnand the column bottom is at the other end of the longitudinal axis of acolumn. When an object to be cushioned is placed onto a cushion whichcontains many such columns 1101, such as is shown in FIG. 3, adepressive force 1108 is applied to the cushion and to the column 1101by the cushioned object. Because the cushion is expected to rest on sometype of supporting surface, such as a base, a reaction force 1109 isprovided by—the supporting surface. The cushion, including the column1101, yields under the weight of the cushioned object. This yielding isa result of compression of the cushioning media and, if the load under aprotruding portion of the cushioned object is high enough, by bucklingor partial buckling of the columns 1101. From FIG. 11, it can be seenthat the depicted column 1101 buckles because the flexible cushion walls1102 and 1103 buckle outward around the periphery of the column, asdepicted by cross-sectional points 1110 and 1111. In other words, thecolumn walls buckle radically outward orthogonally from the longitudinalaxis of the column. This permits the column 1101 to decrease in totallength along its longitudinal axis 1108 and thereby conform to the shapeof protuberances on a cushioned object. Since buckled columns carrycomparatively little load, this results in a cushion that avoidspressure peaks on the cushioned object.

[0165]FIG. 12 depicts a. column 1201 including column walls 1202 and1203 and column interior 1204. The column 1201 has a longitudinal axis1205 which may be oriented in the, cushion parallel to the direction ofmovement of a cushioned object sinking, into the cushion. Thus, thecolumn top end 1206 is at the side of the cushion that contacts thecushioned object, and the column bottom end 1207 is at the side of thecushion that typically will rest on some sort of a base. When an objectto be cushioned is placed against a cushion which contains numerouscolumns 1201, such as is shown in FIG. 3, a depressive force 1208 isapplied to the cushion and to the column 1201 by the cushioned object.Because the cushion is expected to rest on some type of supportingsurface, such as a base, a reaction force 1209 is provided by thesupporting surface. The cushion, including the column 1201, yields underthe weight of the cushioned object. This yielding is a result ofcompression of the cushioning media and, if the load under a protrudingportion of the cushioned object is high enough, by buckling or partialbuckling of the columns. From FIG. 12, it can be seen that the depictedcolumn 1201 buckles because the flexible cushion wall 1202 bucklesoutward from the column center or orthogonal away from the longitudinalaxis of the column at point 1210, while cushion wall 1203 buckles inwardtoward the column center or orthogonal toward the longitudinal axis ofthe column at points 1211. This buckling action causes the column 1201to decrease in total length along its longitudinal axis 1208 and therebyconform to the shape of protuberances on a cushioned object. Point 1210is depicted buckling outward (away from the center of the column) andpoint 1211 is depicted as buckling inward (toward the center of thecolumn). Alternatively, both points 1210 and 1211 could buckle inwardtoward the center of the column or both could buckle outward. Sincebuckled columns carry comparatively little load, this results in acushion that avoids pressure peaks on the cushioned object. Buckling ofa column permits the column to decrease in total length along itslongitudinal axis and thereby conform to the shape of protuberances on acushioned object. This results in a cushion that avoids pressure peakson the cushioned object. It should be noted by the reader that thecolumns 1101 and 1201 depicted in FIGS. 11 and 12 are hollow columnswhich have interiors completely open to the atmosphere and which permitair to travel through the columns to enhance ventilation under thecushioned object. It is also of note that the column 1201 of FIG. 12 hascolumn walls 1202 and 1203 that include fenestrations 1210 (which may beholes or apertures in the column walls) that permit the flow of airbetween adjacent columns, providing an enhanced ventilation effect.Fenestrations are also useful for reducing the weight of the cushioningelement. The greater the size and/or number of fenestrations in columnwalls, the less the cushion weighs. The fenestrations or holes 1210 inthe column walls could be formed by punching or drilling, or they couldbe formed during molding of the cushioning element.

[0166]FIG. 13 depicts an alternative column 1301 including column walls1302 and 1303 and a column interior 1304. The column 1301 has alongitudinal axis 1305 which, in the cushion, may be oriented parallelto the direction in which the cushioned object is expected to sink intothe cushion. Thus, the column top end 1306 is at the side of the cushionthat contacts the cushioned object, and the column bottom end 1307 is atthe side of the cushion that typically faces some sort of a base. Whenan object to be cushioned is placed onto a cushion which contains column1301, such as is shown in FIG. 3, a depressive force 1308 is applied tothe cushion and to the column 1301 by the cushioned object. Because thecushion is expected to rest on some type of supporting surface, such asa base, a reaction force 1309 is provided by the supporting surface. Thecushion, including the column 1301, yields under the weight of thecushioned object. This yielding is a result of compression of thecushioning media and, if the load under a protruding portion of thecushioned object is high enough, by buckling or partial buckling of thecolumns. From FIG. 13, it can be seen that the depicted column 1301buckles because the flexible cushion walls 1302 and 1303 buckle outwardfrom the column center or orthogonal away from the longitudinal axis1305 of the column at points 1311 and 1310. This buckling action allowsthe column 1301 to decrease in total length along its longitudinal axis1305 and thereby conform to the shape of protuberances on a cushionedobject.

[0167] In the embodiment depicted, the column 1301 is a sealed columncontaining air or an inert gas within its interior 1304. Thus, as thecolumn 1301 decreases in length along its longitudinal axis, the gaswithin the column interior 1304 tends to support the column top end 1306and resist the downward movement of the cushioned object. This yields afirmer cushion. Alternatively, open or closed cell (or other) foam orfluid cushioning media could be provided within the interior of thecolumns or within some of them in order to increase the firmness of thecushion.

[0168]FIG. 14 depicts an alternative embodiment of the column. Thecolumn 1401 depicted has column walls 1402 and 1403 and a columninterior 1404. The column interior 1404 is open at column top end 1405and at column bottom end 1406 to permit air to pass through the column1401. Column 1401 has walls 1402 and 1403 which are thicker at theirbottom end 1406 than at their top end 1405, imparting cushions whichinclude such columns with a soft cushioning effect when cushioning anobject that sinks into the cushion to only a shallow depth, butprogressively providing firmer cushioning the deeper the cushionedobject sinks. This configuration of column 1401 permits the constructionof a cushion which accommodates cushioned objects of a very wide varietyof weight ranges. Alternatively, the column walls could be thicker atthe top than at the bottom, the column walls could be stepped, or thecolumn walls could have annular or helical grooves in them to facilitatebuckling under the load of a cushioned object. Additionally, the columninterior could be of a greater interior dimension orthogonal to itslongitudinal axis at one end than at the other. Or the columns could beof varying dimension and shape along their longitudinal axes.

[0169]FIG. 15 depicts a cross section of a cushioning element usingalternating stepped columns. The cushioning element 1501 has a pluralityof columns 1502 each having a longitudinal axis 1503, a column top 1504and a column bottom 1505. The column top 1504 and column bottom 1505 areopen in the embodiment depicted, and the column interior or columnpassage 1506 is unrestricted to permit air flow through the column 1502.The column 1502 depicted has side walls 1507 and 1508, each of which hasthree distinct steps 1509, 1510 and 1511. The columns are arranged sothat the internal taper of a column due to the step on its walls isopposite to the taper of the next adjacent column. This type ofcushioning element could be made using a mold similar to that depictedin FIG. 4.

[0170]FIG. 16 depicts an alternative embodiment of a cushioning element1601. The cushioning element 1601 has a plurality of columns 1602, 1603and 1604, each having a column interior 1605, 1606 and 1607, and columnwalls 1608, 1609, 1610 and 1611. The column walls are made fromcushioning; media, such as the example soft gels herein. In theembodiment of the cushioning element 1601 depicted, the cushioning media1612 has trapped within it a plurality of gas bubbles 1613, 1614 and1615. When a soft gel cushioning medium is used, since the gel is notflowable at the temperatures to which the cushion is expected to beexposed during use, the bubbles remain trapped within the cushioningmedium. The use of bubbles within the cushioning medium reduces theweight of the cushion and softens the cushion to a degree which mightnot otherwise be available. Bubbles may be introduced into thecushioning medium by injecting air, another appropriate gas, or vaporinto the cushioning medium before manufacturing the cushioning element,by vigorously stirring the heated, flowable cushioning medium before itis formed into the shape of a cushion, or by utilizing a cushioningmedium of a composition that creates gas or boils at the temperatures towhich it is subjected during the manufacture of a cushioning element.Blowing agents, some of the uses of which are described in detail belowin connection with the disclosure of the gel material, are also usefulfor introducing gas bubbles into the cushioning medium. Microspheres,which we also discussed in greater detail below, are also useful forintroducing gas pockets into the cushion medium.

[0171]FIG. 17 depicts an embodiment of the cushioning element which hascushioning medium, solid exterior walls 1703 and 1704, a plurality ofcolumns 1705 and column walls 1706 forming the columns. Note thatalthough FIG. 17 shows a cushioning element 1701 with solid walls 1703and 1704, it is possible to make a cushioning element 1701 that hascolumns on its outer walls. The cushioning element is disposed within anoptional cover 1707. A container 1708 with relatively stiff or rigidwalls 1709 and 1710 of approximately the same size and shape as thecushioning element walls 1703 and 1704 is shown. The container 1708 hasa bottom or base 1711 on which the cushioning element is expected torest. The container 1708 walls 1709 and 1710 serve; to restrict theoutward movement of the cushioning element 1701 when a cushioned objectis placed on it. When soft gel is used as a cushioning medium, thecushioning element 1701 would tend to be displaced by the object beingcushioned were the side walls 1709 and 1710 of the container 1711 notprovided. In lieu of a container, any type of appropriate restrainingmeans may be used to prevent side displacement of the cushioning elementin response to the deforming force of a cushioned object. For example,individual plastic plates could be placed against the side walls 1703and 1704 of the cushioning element 1701. Chose plates could be held inplace with any appropriate holder, such as the cover 1707. As anotherexample, an appropriate strap or girdle could be wrapped around allexterior side walls 1703 and 1704 of the cushioning element 1701. Such astrap or girdle would serve to restrain the cushioning element 1701against radial outward displacement in response to a cushioned objectresting on the cushioning element.

[0172]FIG. 18 depicts an alternative embodiment of a cushion 1801 thatincludes a cushioning element 1802 and a cover 1803. The cushioningelement 1802 has side walls 1808 and 1809 about its periphery, the sidewalls 1808 and 1809 in this embodiment being generally parallel with thelongitudinal axis 1810 of a hollow column 1811 of the cushioning element1802. A gap 1806 exists between the cover 1803 and the side wall 1809 ofthe cushioning element. This gap 1806 accommodates the insertion of astiff or rigid reinforcing side wall support 1804 which may be made of asuitable material such as plastic, wood, metal or composite materialsuch as resin and a reinforcing fiber. Similarly, gap 1807 between sidewall 1808 and the cover 1803 may have side wall support 1805 insertedinto it. The side wall supports are configured to restrict thecushioning element from being substantially displaced in an outward orradial direction (a direction orthogonal to the longitudinal axis of oneof the columns of the cushioning element) so that the cushioningelement's columns will buckle to accommodate the shape of a cushionedobject, rather than permitting the cushioning element to squirm out fromunder the cushioned object.

[0173]FIG. 19 depicts an alternative embodiment of a cushioning element1901 including square columns 1908. The cushioning element has outerside walls 1902 and 1903 about its periphery. The reader should notethat although the outer periphery of the cushioning element in FIG. 19is depicted as rectangular, the outer periphery could be of any desiredconfiguration, such as triangular, square, pentagonal, hexagonal,heptagonal, octagonal, any n-sided polygon shape, round, oval,elliptical, heart-shaped, kidney-shaped, quarter moon shaped, n-sidedpolygonal where n is an integer, or of any other desired shape. The sidewalls 1902 and 1903 of the cushioning element 1901 have a peripheralstrap or girdle 1904 about them. The girdle 1904 has reinforcing sidewalls 1905 and 1906 which reinforce the structural stability of sidewalls 1902 and 1903 respectively of the cushioning element 1901. Theembodiment of the girdle 1904 depicted in FIG. 19 has a fasteningmechanism 1907 so that it may be fastened about the periphery of thecushioning element 1901 much as a person puts on a belt. The girdle 1904serves to confine the cushioning element 1901 so that when a cushionedobject is placed on the cushioning element 1901, the cushioning elementwill not tend to squirm out from beneath the girdle 1904. Thus, thecushioning element 1901 will tend to yield and conform to the cushionedobject as needed by having; its cushioning medium compress and itscolumns buckle. FIG. 20 depicts an alternative embodiment of acushioning element 2001. The cushioning element 2001 includes cushioningmedium 2002 such as gel formed into column walls 2003 and 2004 to form acolumn 2005. The column 2005 depicted has a sealed column top 2006 and asealed column bottom 2007 in order to contain a column filler 2008. Thecolumn filler 2008 could be open or closed cell foam, any known fluidcushioning medium such as lubricated spherical objects, or any otherdesired column filler. The cushioning element 2001 depicted has anadvantage of greater firmness compared to similar cushioning elementswhich either omit the sealed column top and column bottom or which omitthe column filler.

[0174]FIG. 21 depicts an alternative embodiment of a cushioning element2101. The cushioning; element 2101 has cushioning medium 2102 formedinto column walls 2103 and 2104. The column walls 2103 and 2104 form acolumn interior 2105. The column 25 2106 has an open column top 2107 anda closed column bottom 2108. In the embodiment depicted, the column 2107has a firmness protrusion 2109 protruding into the column interior 2105from the column bottom 2108. The firmness protrusion 2109 depicted iswedge or cone shaped, but a firmness protrusion could be of an desiredshape, such as cylindrical, square, or otherwise in cross section alongits longitudinal axis. The purpose of the firmness protrusion 2109 is toprovide additional support within a buckled column for the portion of acushioned object that is causing the buckling. When a column of thisembodiment buckles, the cushioning element will readily yield until thecushioned object begins to compress the firmness protrusion. At thatpoint, further movement of the cushioned object into the cushion isslowed, as the cushioning medium of the firmness support needs to becompressed or the firmness support itself needs to be caused to bucklein order to achieve further movement of the cushioned object into thecushioning medium.

[0175] Referring now to FIG. 22, in another embodiment of the cushion,multiple individual cushioning elements 2201 a, 2201 b, 2201 c, etc. areprovided within a single cushion 2200. In such embodiments, the cushionsare positioned side-to-side, with or without other materials between theindividual cushions, and with or without connecting the individualcushions to one another. For example, sixty-four cushions, each having athickness of four inches, and four sides each two inches in length, canbe placed in an eight-by-eight arrangement to form a four inch thicksquare cushion having sixteen inch sides. Such cushions may be usefulwhere different cushioning characteristics are desired on differentportions of a cushion. Different cushioning characteristics are achievedthrough varying the materials and/or configurations of the individualcushions.

[0176] With reference to FIGS. 23a, 23 b, 23 c and 23 d, anotherembodiment of a cushion 2301 is shown. Embodiment 2301 includes a firstcushioning medium 2302 which forms a cover and a second cushioningmedium 2303 which fills the cover. First cushioning medium 2302 may beelastomeric gel material, which is disclosed in detail below. Secondcushioning medium 2303 may be the visco-elastomeric material that isdisclosed in detail below.

[0177] Embodiment 2301 also includes columns 2304, column walls 2305 andan outer periphery 2306. Columns 2304 are formed through cover 2302 andlined with cushioning medium 2302. With reference to FIGS. 23a and 23 b,where two adjacent columns 2304 a and 2304 b are separated only by athin column wall 2305 a (e.g., a column wall having a thickness of onlyabout 0.1 inch or less), the column wall may be made from cushioningmedium 2302. Where two adjacent columns 2304 c and 2304 d are separatedby a thicker column wall 2305 c, the column wall may include a cover2302 of the first cushioning medium and is filled with second cushioningmedium 2303.

[0178] The use of multiple cushioning media in cushion 2301 facilitatestailoring of the rebound, pressure absorption, and flow characteristicsof the cushion. Compressibility of cushion 2301 also depends upon theamount of spacing between columns and the formulations of the firstsecond cushioning media 2302 and 2303, respectively.

[0179]FIGS. 24a and 24 b illustrate another embodiment of the cushioningelement 2401. Referring to FIG. 24b, embodiment 2401 includes acushioning medium 2402, a coating 2403 adhered to the cushioning medium,columns 2404, column walls 2405 that separate the columns, and an outerperiphery 2406. Cushioning medium 2402 of embodiment 2401 may be tacky,which facilitates adhesion of coating 2403 thereto. An examplecushioning medium 2402 for use in embodiment 2401 is disclosed in detailbelow. Coating 2403 may be a particulate material, including withoutlimitation lint, short fabric threads, talc, ground cork, microspheres,and others. However, coating 2403 may me made from any material thatwill form a thin, pliable layer over cushioning medium 2402, includingbut not limited to fabrics, stretchable fabrics, long fibers, papers,films, and others.

[0180]FIGS. 25a, 25 b, 25 c, 25 d, 25 e and 25 f show another embodimentof a cushioning element 2501. Embodiment 2501 includes cushioning medium2502, a first set of columns 2503 which are oriented along a first axisx, a second set of columns 2504 which are oriented along a second axisy, a third set of columns 2505 which are oriented along a third axis z,column walls 2506 located between the columns, and an outer periphery2507. As an example, axis x is perpendicular to both axis y and axis zand axis y is perpendicular to axis z. Columns 2503 and 2504, 2503 and2505, and/or 2504 and 2505 may intersect each other. FIGS. 25a, 25 b and25 c illustrate a cushion 2501 a wherein columns 2503 a intersectcolumns 2504 and columns 2503 b intersect columns 2505. FIGS. 25d, 25 eand 25 f depict a cushion 2501 b wherein each of columns 2503 intersectboth columns 2504 and columns 2505. Alternatively, none of the columnsmay intersect any other columns. Other variations of intersection and/ornon-intersecting columns are also within the scope.

[0181] The spacing and pattern with which each set of columns ispositioned determines the total volume of cushioning medium 2502 withinthe volume of space occupied by the cushioning element 2501. As thevolume of cushioning medium 2502 within the volume of space occupied bythe cushioning element 2501 decreases, the cushion becomes lighter andeasier to compress. Thus, the spacing and pattern of each set of columnsmay be varied to provide a cushion of desired weight andcompressibility. Cushioning elements which have only two sets of columnsor more than three sets of columns are also within the scope ofembodiment 2501.

[0182] With reference to FIG. 26, another embodiment of cushioningelement 2601 is shown which includes a first set of columns 2603 whichare oriented along a first axis x, a second set of columns 2604 whichare oriented along a second axis y, and a third set of columns 2605which are oriented along a third axis z. As can be seen in FIG. 26,columns 2603, 2604 and 2605 may be thin. Column walls 2606, which aremade from a cushioning medium 2602, surround each of the columns. Thecushion 2601 shape is defined in part by an outer periphery 2607. As anexample, axis x is perpendicular to both axis y and axis z and axis y isperpendicular to axis z. Similar to the cushion of embodiment 2501,columns 2603, 2604 and 2605 may or may not intersect any other columns.Likewise, the spacing between adjacent columns and the arrangement ofeach of the columns determine the total volume of cushioning medium 2602within the volume of space occupied by the cushioning element 2601. Asthe volume of cushioning medium 2602 within the volume of space occupiedby the cushioning element 2601 decreases, the cushion becomes lighterand easier to compress. Thus, the spacing and arrangement of columns maybe varied to provide a cushion of desired weight and compressibility.Cushions with only two sets of columns or more than three sets ofcolumns are also within the scope of embodiment 2601.

[0183] Referring now to FIGS. 27a, 27 b and 27 c, another embodiment ofa cushioning element 2701 is shown. Embodiment 2701 includes cushioningmedium 2702, a first set of columns 2703 which are oriented along afirst axis x, a second set of columns 2704 which are oriented along asecond axis y, a third set of columns 2705 which are oriented along athird axis z, column walls 2706 located between the columns, cavities2707 formed within the column walls and an outer periphery 2708. As anexample, axis x is perpendicular to both axis y and axis z and axis y isperpendicular to axis z. Columns 2703 and 2704, 2703 and 2705, and/or2704 and 2705 may intersect each other, as in embodiments 2501 and 2601.Alternatively, none of the columns may intersect any other column. Thespacing and pattern with which each set of columns is positioned and thenumber of cavities 2706 formed within the column walls 2707 determinethe total volume of cushioning medium 2702 within the volume of spaceoccupied by the cushioning element 2701. As the volume of cushioningmedium 2702 within the volume of space occupied by the cushioningelement 2701 decreases, the cushion becomes lighter and easier tocompress. Thus, the spacing and pattern of each set of columns may bevaried to provide a cushion of desired weight and compressibility.Similarly, the size and spacing of the cavities 2706 within the columnwalls 2707 may also be varied to provide a cushion of desired weight andcompressibility. Cushioning elements which have only two sets of columnsare also within the scope of embodiment 2701.

[0184]FIG. 28 illustrates yet another embodiment of a cushioning element2801, which has a contoured upper surface. The cushion 2801 shown inFIG. 28 has columns 2803 and 2804 of different heights and column walls2805 and 2806 of different heights. However, a contoured cushionaccording to embodiment 2801 could include columns and column wallshaving any number of different heights. Embodiment 2801 also includescushioning medium 2802 and an outer periphery 2807. The variability ofcolumn and column wall height in embodiment 2801 imparts the cushionwith areas having different compressibility and firmnesscharacteristics.

[0185] As seen in FIG. 28, cushion 2801 has two distinct levels ofcolumns. The adjacent longer columns 2803 are grouped together, referredto as a set of isolated columns 2808. The shorter columns 2804, whichare located between sets 2808, tie cushion 2801 together and form acushion base 2809.

[0186] As an example of the use of cushion 2801, a cushioned objectwhich comes into contact with the top surface thereof will firstcompress columns 2803, causing the column walls 2805 to buckle. The freearea between isolated column sets 2808 enhances the bucklability ofcolumns 2803. In other words, columns 2803 buckle more easily than wouldcolumns of the same size, separated by column walls of the samethickness and made from the same material in a cushion having columns ofonly one general height. If the load of the cushioned object causescomplete buckling of columns 2803, columns 2804, which have a greaterresistance to buckling than the long columns, provide a secondarycushioning effect, which is more like that of a cushion with columns ofone general length.

[0187] Referring now to FIG. 29, a cushion 2901 is shown which includesa cushioning medium 2902, columns 2903, column walls 2904, and an outerperiphery 2905. Cushioning medium includes a plurality of cells 2906×,2906 b, 2906 c, etc. which are filled with gas or another cushioningmedium. The cushion 2901 depicted in FIG. 29 has open cells 2906.Alternatively, cushion 2901 may have only closed cells or a combinationof open and closed cells. Cells 2906 x, 2906 b, 2906 c, etc. may be ofany size and may be dispersed throughout cushioning medium at anydensity or concentration that will provide the desired cushioning andweight characteristics.

[0188] Referring now to FIGS. 30a and 30 b, alternative embodiments ofthe cushions 3001 and 3001 which have light weight column walls 3004 and3004′, respectively, are shown. Cushions 3001 and 3001′ also include acushioning medium 3002 and 3002′, columns 3003 and 3003′ and an outerperiphery 3005 and 3005′, respectively. Column walls 3004 and 3004′ eachinclude a matrix 3006 and 3006′, respectively, within which are locatedseveral voids 3007×, 3007 b, 3007 c, etc. and 3007 x′, 3007 b′, 3007 c′,etc. and 3008 a, 3008 b, etc., respectively. Matrix 3006 is made fromcushioning medium 3002, 3002′. Voids 3007, 3007′, 3008 are hollow areasformed within matrix 3006 which lighten column walls 3004, 3004′. Asexample, voids 3007, 3007′ are filled with gas or any other substancewhich has a density (i.e., specific gravity) less than that ofcushioning medium 3002, 3002′. As an example, voids 3007, 3007′ are opencelled (i.e., continuous with the outer surface of cushion 3001, 3001′and exposed to the atmosphere).

[0189]FIG. 30a shows cushion 3001, the column walls 3004 of whichinclude a matrix 3006 which forms voids 3007 x, 3007 b, 3007 c, etc.having a multi-sided irregular shape. Column walls which have matricesand pits of other configurations are also within the scope of thecushioning elements. Embodiment 3001 may be formed by removal ordestruction of volume occupying objects which are dispersed throughoutthe cushioning medium as cushion 3001 is formed.

[0190]FIG. 30b shows cushion 3001 having a matrix 3006 formed fromrandomly oriented short tubes 3009 a, 3009 b, 3009 c, etc. which formsvoids 3007 and 3008. Voids 3007 a, 3007 b′, 3007 c′, etc. are formedwithin short tubes 3009 a, 3009 b, 3009 c, etc. and are generallycylindrical in shape. Matrix 3006′ also includes irregularly shapedsecondary voids 3008 a, 3008 b, 3008 c, etc. which are formed by theexterior surfaces of tubes 3009 between adjacent tubes.

[0191] It is contemplated that the hollow portion of the column willtypically be of uniform cross section throughout its length, but this isnot necessary for all embodiments. For example, in a column having acircular cross section orthogonal to its longitudinal axis, the diameterof the circle could increase along its length, and adjacent columnscould correspondingly decrease along their length (i.e. the columnswould be formed as opposing cones). As another example, the column wallscould all thicken from one cushion surface to another to facilitate theuse of tapered cores (which create the hollow portion of the columns) inthe manufacturing tool, which tapering facilitates the removal of thecores from the gel.

[0192] As an example the columns of the cushioning element be open attheir top and bottom. However, the columns can be bonded to or integralwith a face sheet on the top or bottom or both, over all or a portion ofthe cushion. Or the columns can be interrupted by a sheet of gel orother material at their midsection which is like a face sheet exceptthat it cuts through the interior of a cushioning element.

[0193] In an example embodiment of the cushioning element the columnwalls are not perforated. However, perforated walls and/or face sheetsare within the scope hereof. The perforation size and density can bevaried by design to control column stiffness, buckling resistance, andweight, as well as to enhance air circulation.

[0194] Wall thickness of the columns can be approximately equalthroughout the cushioning, element for uniformity, but in specialapplications of the cushion, wall thickness may be varied to facilitatemanufacturing or to account for differing expected weight loads acrossthe cushion or for other reasons.

[0195] Typical cushions in the art are ordinarily one piece, but thecushion can be constricted from more than one discontinuous cushioningelement. For example, three one-inch thick cushions hereof can bestacked to make a three-inch thick cushion hereof, with or without othermaterials between the layers, and with or without connecting the threelayers to one another.

[0196] The cushioning element hereof can be used alone or with a cover.A cover can be desirable when used to cushion a human body to mask thesmall pressure peaks at the edges of the column walls. This is notnecessary if the gel used is soft enough to eliminate these effects, butmay be desirable if firmer gels are used. Covers can also be desirableto keep the gel (which can tend to be sticky) clean. If used, a covershould be pliable or stretchable so as not to overly reduce the grosscushioning effects of the columns compressing and/or buckling. A coverwould also permit air to pass through it to facilitate air circulationunder the cushioned object.

[0197] While it is envisioned that the immediate application of thecushion is to cushion human beings (e.g., seat cushions, mattresses,wheelchairs cushions, stadium seats, operating table pads, etc.),Applicant also anticipates that other objects, including withoutlimitation, animals (e.g. between a saddle and a horse), manufacturedproducts (e.g., padding between a manufactured product and a shippingcontainer), and other objects may also be efficiently cushioned.

[0198] As an example, the columns in the cushion are oriented with theirlongitudinal axis generally parallel to the direction of gravity so thatthey will buckle under load from a cushioned object rather than collapsefrom side pressure. Some type of wall or reinforcement may be providedabout the periphery of the cushioning element in order to add stabilityto the cushioning element and in order to ensure that the bucklingoccurs in order to decrease column length under a cushioned object.

[0199] The cushioning element may be described as a gelatinouselastomeric or gelatinous visco-elastomeric material (i.e. gel)configured as laterally connected hollow vertical columns whichelastically sustain a load up to a limit, and then buckle beyond thatlimit. This produces localized buckling in a cushioning element beneatha cushioned object depending upon the force placed upon the cushioningelement in a particular location. As a result, protruding portions ofthe cushioned object can protrude into the cushion without beingsubjected to pressure peaks. As a result, the cushioning elementdistributes its supportive pressure evenly across the contact area ofthe cushioned object. This also maximizes the percentage of the surfacearea of the cushioned object that is in contact with the cushion.

[0200] Each individual column wall can buckle, markedly reducing theload carried by that column and causing each column to be able toconform to protuberances of the cushioned object. Buckling may bedescribed as the localized crumpling of a portion of a column, or thechange in primary loading of a portion of a column from compression tobending. In designing structural columns, such as concrete or steelcolumns for buildings or bridges, the designer seeks to avoid bucklingbecause once a column has buckled, it curves. Far less load than whennot buckled. In the columns of this cushion, however, buckling works toadvantage in accomplishing the objects. The most protruding parts of thecushioned object cause the load on the columns beneath those protrudingparts to have a higher than average load as the object initially sinksinto the cushion. This higher load causes the column walls immediatelybeneath the protruding portion of the cushioned object to buckle, whichmarkedly reduces the load on the protruding portion. The surroundingcolumns, which have not exceeded the buckling threshold, take up theload which is no longer carried by the column(s) beneath the mostprotruding portion of the cushioned object.

[0201] As an example of the desirability of the buckling provided by thecushioning element, consider the dynamics of a seat cushion. The area ofa seated person which experiences the highest level of discomfort whenseated without a cushion (such as on a wooden bench) or on a foamcushion is the tissue that is compressed beneath the most protrudingbones (typically the ischial tuberosities). When the cushioning elementis employed, the area beneath the protruding portions will have columnsthat buckle, but the remainder of the cushioning element should havecolumns (which are beneath the broad, fleshy non-bony portion of theperson's posterior) which will withstand the load placed on them and notbuckle. Since the broad fleshy area over which the pressure issubstantially equal is approximately 95% of the portion of the personsubjected to sitting pressure, and the area beneath the ischialtuberosity is subjected to less than average pressure due to the locallybuckled gel columns (in approximately 5% of that area), the person iswell supported and the cushion is very comfortable to sit on.

[0202] As another example, the cushioning element is useful in a bedmattress. The shoulders and hips of a person lying on his/her side wouldbuckle the columns in the cushioning element beneath them, allowing theload to be picked up in the less protruding areas of the person's bodysuch as the legs and abdomen. A major problem in prior art mattresscushions is that the shoulders and hips experience too much pressure andthe back is unsupported because the abdomen receives too littlepressure. The cushion hereof offers a solution to this problem bytending, to equalize the pressure load through local buckling underprotruding body parts.

[0203] The square columns of FIG. 7 or 8 in the cushion are believed byApplicant to have the best balance between lateral stability (resistanceto collapse from side loads) and light weight (which also corresponds togood air circulation and low thermal transfer). Some other types ofcolumns, such those depicted in the other figures or mentioned elsewhereherein, have more cushioning media (typically gel) per cubic inch ofcushion for a given level of cushioning support. Thus, the resultingcushions are heavier and have a higher rate of thermal transfer. Theyare also more costly to manufacture due to the increased amount ofcushioning media required. However, columns with oval, circular ortriangular cross sections can be used for some cushioning applicationsbecause they have a greater degree of lateral stability than square orhoneycomb columns since triangles form a braced structure and circlesand ovals form structurally sound arches when considered from a lateralperspective. Honeycomb columns such as those shown in FIGS. 2, 4, 5, 7,8, 9 and 10 generally have the least gel per cubic inch of cushion for agiven level of support, but have little lateral stability.

[0204] The cushions hereof differ from prior art gel cushions in that,while prior art gel cushions come in a variety of shapes, many areessentially a solid mass. When a cushioned object attempts to sink intoa prior art gel cushion, the cushion either will not allow the sinkingin because the non-contact portions of the cushion are constrained fromexpanding, or the cushion expands undesirably by pushing gel away fromthe most protruding parts of the cushioned object in a manner whichtends to increase the reactive force exerted by the gel against areas ofthe cushioned object which surround the protrusions. In the cushionhereof, the gel has enough hollow space to allow sinking in withoutexpanding the borders of the cushion, so the problem is alleviated.

[0205] Another problem with many prior art gel cushions is their weight.For example, a wheelchair cushion made of prior art gel with dimensionsof 18″×16″×3.5″ would weigh 35-40 pounds, which is unacceptable to manywheelchair users. A cushion having the same dimensions would weighapproximately seven pounds or less. To be an acceptable weight forwheelchairs, a typical prior art wheelchair gel cushion is made only 1″thick. To prevent bottoming out through such a thin cushion, the makersincrease the rigidity of the gel, which decreases the gel'ssemi-hydrostatic characteristics, ruining the gel's ability to equalizepressure. Thus, many thin gel cushions relieve pressure no better than afoam cushion. The cushion can be a full 3.5 inches thick needed to allowsinking in for a human user which is in turn needed to equalize pressureand increase the surface area under pressure, while still being lightweight.

[0206] The cushions hereof differ from prior art honeycomb cushions inpart in that gel is used instead of thermoplastic film or thermoplasticelastomer film. Also, a comparatively thick gel is used for the walls ofthe columns, as compared to very thin films made of comparatively muchmore rigid thermoplastic film or thermoplastic elastomer film. If thickwalls were used in prior art honeycomb cushions, the rigidity ofavailable thermoplastics and available thermoplastic elastomers wouldcause the cushion to be far too stiff for typical applications. Also,the use of comparatively hard, thin walls puts the cushioned object atincreased risk. When the load on a prior art honeycomb cushion exceedsthe load carrying capability of virtually all of the columns (i.e., theyall buckle), the cushioned object bottoms out onto a relatively hard,rigid, thin pile of thermoplastic film layers. In that condition, thecushioned object is subjected to pressures similar to the pressures itwould experience with no cushion at all. The cushioned object is thus atrisk of damaging pressures on its most protruding portions.

[0207] In comparison, if the same bottoming out occurs on the cushionhereof, the most protruding portions of the cushioned object would bepressed into a pile of relatively thick, soft gel layers, which wouldadd up to typically 20% of the original thickness of the cushion. Thus,the risk of bottoming, out is substantially lowered.

[0208] Another difference between prior art thermoplastic honeycombcushions and the cushion hereof is that the configuration of the cushionis not limited to honeycomb columns, but can take advantage of thevarying properties offered by columns of virtually any cross sectionalshape. The prior art thermoplastic honeycomb cushions are so laterallyunstable that at least one face sheet must be bonded across the opencells. This restricts the air circulation, which is only somewhatrestored if small perforations are made in the face sheet or cells.While face sheets and perforations are an option on the cushions hereof,the alternative cross sectional shapes of the columns (e.g., squares ortriangles) make face sheets unnecessary due to increased lateralstability and thus perforations are unnecessary since both ends of theconfiguration of the column can be open to the atmosphere.

[0209] The maximum thickness of the walls of the columns of the cushionhereof should be such that the bulk density of the cushion is less than50% of the bulk density if the cushion were completely solid gel. Thus,at least 50% of the volume of space occupied by the cushioning elementis occupied by a gas such as air and the remainder is occupied by gel.The minimum thickness of the walls of the columns is controlled by threefactors:

[0210] (1) manufacturability; (2) the amount of gel needed forprotection of the cushioned object in the event of all columns buckling;and (3) the ability to support the cushioned object without buckling themajority of the columns. The thickness would be such that the columnsunder the most protruding parts of the cushioned object are buckled, andthe remaining columns are compressed in proportion to the degree ofprotrusion of the cushioned object immediately above them but are notbuckled.

[0211] B. Cushion Materials

[0212] The cushioning media used to manufacture the cushioning elementcan soft gel. This; assures that the cushion will yield under acushioned object by having buckling columns and by the cushioning mediumitself compressing under the weight of the cushioned object. The softgel will provide additional cushioning and will accommodate unevensurfaces of the cushioned object. Nevertheless, firmer gels are alsouseful in the cushioning element, provided that the gel is soft enoughto provide acceptable cushioning for the object in the event that all ofthe columns buckle. Since, with a given type of gel, there is typicallya correlation between softness and Young's modulus (stiffness) (i.e., asofter gel is less stiff), and since there is a correlation betweenYoung's modulus and the load carrying capability of a column beforebuckling, there is typically a need for firmer gels in cushions whichwill carry a higher load. However, there are other alternatives forincreasing a cushion's load carrying capability, such as increasing thecolumn wall thickness, so that the softness of the gel can be selectedfor its cushioning characteristics and not solely for its load bearingcharacteristics, particularly in cases where cushion weight is not afactor. Any gelatinous elastomer or gelatinous visco-elastomer with ahardness on the Shore A scale of less than about 15 is useful in thecushioning element. The cushioning medium can have a Shore A hardness ofabout 3 or less. Or materials which have a hardness of less than about800 gram bloom can be used. Such materials are too soft to measure onthe Shore A scale. Gram Bloom is defined as the gram weight required todepress a gel a distance of four millimeters (4 mm) with a piston havinga cross-sectional area of one square centimeter (1 cm) at a temperatureof about 23° C. The example gel may be cohesive at the normal useabletemperatures of a cushioning element. The example gel will not escapefrom the cushioning element if the cushioning element is punctured. Theexample gel has shape memory so that it tends to return to its originalshape after deformation.

[0213] The cushioning media or gel should also be strong enough towithstand the loads and deformations that are ordinarily expected duringthe use of a cushion. For a given type of gel, there is typically acorrelation between softness and strength (i.e., softer gels are not asstrong as harder gels).

[0214] Because of their high strength even in soft formulations, theirlow cost, their ease of manufacture, the variety of manufacturingmethods which can be used, and the wide range of Young's modulus whichcan be formulated while maintaining the hydrostatic characteristics of agel, the gel formulations which follow are example gels to be used incushions.

[0215] Applicant believes that the reader might benefit from a generalbackground discussion of the chemistry underlying the gels prior toreading about the example formulations.

[0216] 1. Chemistry of Plasticizer-Extended Elastomers

[0217] A basic discussion of the chemical principles underlying thecharacteristics and performance of plasticizer-extended elastomers isprovided below to orient the reader for the later discussion of theparticular chemical aspects of the material for use in the cushions

[0218] The example gel cushioning medium is a composition primarily oftriblock copolymers and plasticizers, both of which are commonlyreferred to as hydrocarbons. Hydrocarbons are elements which are made upmainly of Carbon (C) and Hydrogen (H) atoms. Examples of hydrocarbonsinclude gasoline, oil, plastic and other petroleum derivatives.

[0219] Referring to FIG. 31a, it can be seen that a carbon atom 3110typically has four covalent bonding sites “”. FIG. 31b shows a hydrogenatom 3112, which has only one covalent bonding site . With reference toFIG. 31c, which represents a four-carbon molecule called butane, a“covalent” bond, represented at 3116 as “—”, is basically a very strongattraction between adjacent atoms. More specifically, a covalent bond isthe linkage of two atoms by the sharing of two electrons, onecontributed by each of the atoms. For example, the first carbon atom3118 of a butane molecule 3114 shares an electron with each of threehydrogen atoms 3120, 3122 and 3124, represented as covalent bonds 3121,3123 and 3125, respectively, accounting for three of carbon atom 3118'savailable electrons. The final electron is shared with the second carbonatom 3126, forming covalent bond 3127. When atoms are covalently boundto one another, the atom-to-atom covalent bond combination makes up amolecule such as butane 3114. An understanding of hydrocarbons, theatoms that make hydrocarbons and the bonds that connect those atoms isimportant because it provides a basis for understanding the structureand interaction of each of the components of the example gel material.

[0220] As mentioned above, the example gel cushioning material utilizestriblock copolymers. With reference to FIGS. 32a and 32 b, a triblockcopolymer is shown. Triblock copolymers 3210 are so named because theyeach have three blocks-two endblocks 3212 and 3214 and a midblock 3216.If it were possible to grasp the ends of a triblock copolymer moleculeand stretch them apart, each triblock copolymer would have a string-likeappearance (as in FIG. 32a), with an endblock being located at each endand the midblock between the two endblocks.

[0221]FIG. 33a depicts the example endblocks of the copolymer mostexample for use in the example gel material, which are known asmonoalkenylarene polymers 3310. Breaking the term “monoalkenylarene”into its component parts is helpful in understanding the structure andfunction of the endblocks. “Aryl” refers to what is known as an aromaticring bonded to another hydrocarbon group. Referring now to FIG. 33b,benzene 3312, one type of aromatic ring, is made up of six carbonmolecules 3314, 3316, 3318, 3320, 3322 and 3324 bound together in aring-like formation. Due to the ring structure, each of the carbon atomsis bound to two adjacent carbon atoms. This is possible because eachcarbon atom has four bonding sites. In addition, each carbon atom C of abenzene molecule is bound to only one hydrogen atom H. The remainingbonding site on each carbon atom C is used up in a double covalent bond3326, 3327, which is referred to as a double bond. Because each carbonatom has only four bonding sites, double bonding in an aromatic ringoccurs between a first carbon and only one of the two adjacent carbons.Thus, single bonds 3116 and double bonds 3326 alternate around thebenzene molecule 3312. With reference to FIG. 33c, in an aryl group3328, one of the carbons 3330 is not bound to a hydrogen atom, whichfrees up a bonding site R for the aryl group to bond to an atom or groupother than a hydrogen atom.

[0222] Turning now to FIG. 33d, “alkenyl” 3332 refers to a hydrocarbongroup made up of only carbon and hydrogen atoms, wherein at least one ofthe carbon-to-carbon bonds is a double bond 3334 and the hydrocarbongroup is connected to another group of atoms R′, where R′ represents theremainder of the hydrocarbon molecule and can include a single hydrogenatom. Specifically, the “en” signifies that a double bond is presentbetween at least one pair of carbons. The “yl” means that thehydrocarbon is attached to another group of atoms. For example, FIG. 33eshows a two carbon group having a double bond between the carbons, whichis called etheny13336. Similarly, FIG. 3f illustrates a three carbongroup having a double bond between two of the carbons, which is calledpropenyl 3338. Referring again to FIG. 33a, in a monoalkenylarene suchas styrene, a carbon 3340 with a free bonding site of an alkenyl group3332 is bonded to the aryl group 3328 at carbon atom 3330, which alsohas a free bonding site. In reference to FIG. 33c, aryl group 3328 ispart of a monoalkenylarene molecule when R is an alkenyl group. The“mono” of monoalkenylarene explains that only one alkenyl group isbonded to the aryl group.

[0223] The monoalkenylarene end blocks of a triblock copolymer arepolymerized. Polymerization is the process whereby monomers areconnected in a chain-like fashion to form a polymer. FIG. 34a depicts apolymer 3410, which is basically a large chain-like molecule formed frommany repeating smaller molecules, called monomers, M1, M2, M3, etc.,that are bonded together. P and P′ represent the ends of the polymer,which are also made up of monomers FIG. 34b illustrates amonoalkenylarene end block polymer 3414, which is a chain ofmonoalkenylarene molecules 3416 a, 3416 b, 3416 c, etc. The chain ofFIG. 34b is spiral, or helical, in shape due to the bonding anglesbetween styrene molecules. P represents an extension of the endblockpolymer helix in one direction, while P′ represents an extension of theendblock polymer helix in the opposite direction.

[0224] As FIG. 34c shows, monoalkenylarene molecules are attracted toone another by a force that is weaker than covalent bonding. The primaryweak attraction between monoalkenylarene molecules is known ashydrophobic attraction. An example of hydrophobic attraction is theattraction of oil droplets to each other when dispersed in water.Therefore, in its natural, relaxed state at room temperature, amonoalkenylarene polymer resembles a mass of entangled string 3414, asdepicted in FIG. 34d. The attraction of monoalkenylarene molecules toone another creates a tendency for the endblocks to remain in anentangled state. Similarly, different monoalkenylarene polymers areattracted to each other. The importance of this phenomenon will becomeapparent later in this discussion.

[0225] Like the end blocks of a triblock copolymer, the midblock is alsoa polymer. The example triblock copolymer for use in the elastomercomponent of the example cushioning medium includes is an aliphatichydrocarbon midblock polymer. Traditionally, “aliphatic” meant that ahydrocarbon was “fat like” in its chemical behavior. Referring to FIGS.35a through 35 c, which, for simplicity, do not show the hydrogen atoms,an “aliphatic compound” is now defined as a hydrocarbon compound whichreacts like an alkane 3510 (a hydrocarbon molecule having only singlebonds between the carbon atoms), an alkene 3512 (a hydrocarbon moleculewherein at least one of the carbon-to-carbon bonds is a double bond)3514, an alkyne (a hydrocarbon molecule having a triple covalent bond3515 between at least one pair of carbon atoms), or a derivative of oneor a combination of the above.

[0226] Referring now to FIG. 35d, which omits the bound hydrogen atomsfor simplicity, aliphatic hydrocarbons known as conjugated dienes 3516are depicted. These are the example midblock monomers used in thetriblock copolymers of the example gel material. A “diene” is ahydrocarbon molecule having two (“di”) double bonds (“ene”).“Conjugated” means that the double bonds 3518 and 3520 are separated byonly one single carbon-to-carbon bond 3522. In comparison, FIG. 35eshows a hydrocarbon molecule having two double carbon-to-carbon bondsthat are separated by two or more single bonds, 3530, 3532, etc., whichis referred to as an “isolated diene” 3524. When double bonds areconjugated, they interact with each other, providing greater stabilityto a hydrocarbon molecule than would the two double bonds of an isolateddiene.

[0227]FIGS. 36a through 36 d illustrate examples of various monomersuseful in the midblock of the triblock copolymers example for use in theelastomer component of the example gel cushioning medium, includingmolecules (monomers) such as ethylene-butylene (EB) 3612,ethylene-propylene (EP) 3614, butadiene (B) 3616 (either hydrogenated ornon-hydrogenated) and isoprene (I) 3618 (either hydrogenated ornon-hydrogenated). The different structures of these molecules providethem with different physical characteristics, such as differingstrengths of covalent bonds between adjacent monomers. The variousstructures of monomer molecules also provides for different types ofinteraction between distant monomers on the same chain (e.g., when themidblock chain folds back on itself, distant monomers may be attractedto one another by a force weaker than covalent bonding, such ashydrophobic interaction, hydrophilicinteraction, polar forces or VanderWaals forces).

[0228] Referring to FIGS. 36a and 36 b, x, y and n each represent anintegral number of each bracketed unit: “x” is the number of repeatingethylene (—CH2-CH2-) units, “y” is the number of repeating butylene (inFIG. 36a) or propylene (in FIG. 36b) units, and “n” is the number ofrepeating poly(ethylene/butylene) units. Numerous configurations arepossible. As shown in FIGS. 37a through 37 d, the midblock may contain(i) only one type of monomer, EB, EP, B or I or, as FIGS. 37e and 37 fillustrate, (ii) a combination of monomer types EB and EP or B and 1,providing for wide variability in the physical characteristics ofdifferent midblocks made from different types or combination of types ofmonomers. The interaction of physical characteristics of each molecule(monomer and block) determines the physical characteristics of thetangible, visible material. In other words, the type or types of monomermolecules which make up the midblock polymer play a role in determiningvarious characteristics of the material of which the midblock is a part.

[0229] Attributes such as strength, elongation, elasticity orvisco-elasticity, softness, tackiness and plasticizer retention are, inpart, determined by the type or types of midblock monomers. For example,referring again to FIG. 37a, the midblock polymer 3216 of a triblockcopolymer containing material may be made up primarily or solely ofethylene-butylene monomers EB, which contribute to that material'sphysical character. With reference to FIG. 37e, in comparison to thematerial having a midblock made up solely of EB, a similar triblockcontaining material, wherein the midblock polymer 3216 of the triblocksare made up of a combination of butadiene B and isoprene I monomers, mayhave greatly increased strength and elongation, similar elasticity orvisco-elasticity and softness, reduced tackiness and reduced plasticizerbleed.

[0230] The monomer units of the midblock have an affinity for eachother. However, the hydrophobic attraction of the midblock monomers foreach other is much weaker than the non-covalent attraction of the endblock monomers for one another.

[0231] Referring now to FIG. 38a, which shows apolystyrene-poly(butadiene+isoprene) polystyrene triblock copolymer, ina complete triblock copolymer 3810, each end 3812 and 3814 of midblockchain 3216 is covalently bound to an end block 3212 and 3214. P and P″represent the remainder of the endblock polymers 3212 and 3214respectively. P′ represents the central portion of midblock polymer3216. Many billions of triblock copolymers combine to form a tangiblematerial. The triblock copolymers are held together by the high affinity(i.e., hydrophobic attraction) that monoalkenylarene molecules have forone another. In other words, as FIG. 38b illustrates, the endblocks ofeach triblock copolymer molecule, each of which resemble an entangledmass of string 3414, are attracted to the endblocks of another triblockcopolymer. When several endblocks are attracted to each other, they forman accretion of endblocks, called a domain or a glassy center 3816.Agglomeration of the endblocks occurs in a random fashion, which resultsin a three-dimensional network 3818 of triblocks, the midblock 3216 ofeach connecting endblocks 3212 and 3214 located at two different domains3816 a and 3816 b. In addition to holding the material together, thedomains of triblock copolymers also provide it with strength andrigidity.

[0232] Plasticizers are generally incorporated into a material toincrease the workability, pliability and flexibility of that material.Incorporation of plasticizers into a material is known asplasticization. Chemically, plasticizers are hydrocarbon molecules whichassociate with the material into which they are incorporated, asrepresented in FIG. 39a. In the example gel material, plasticizermolecules 3910 associate with the triblock copolymer 3210, and increaseits workability, softness, elongation and elasticity orvisco-elasticity. Depending upon the type of plasticizer used, theplasticizer molecules associate with either the endblocks, the midblock,or both. In order to preserve the strength of the example gel materials,Applicant prefers the predominant use of plasticizers 3910 whichassociate primarily with midblock polymer 3216 of triblock copolymer3818, rather than with the end blocks. However, plasticizers whichassociate with the end blocks may also be useful in some formulations ofthe example gel material. Plasticizers are also desired which associatewith the principle thermoplastic polymer component of the gel material.

[0233] Chemists have proposed four general theories to explain theeffects that plasticizers have on certain materials. These theories areknown as the lubricity theory, the gel theory, the mechanistic theoryand the free volume theory.

[0234] The lubricity theory, illustrated in FIGS. 39b through 39 d,assumes that the rigidity of a material (i.e., its resistance todeformation) is caused by intermolecular friction. Under this theory,plasticizer molecules 3910 lubricate the large molecules, facilitatingmovement of the large molecules over each other. See generally,Jacqueline 1. Kroschwitz, ed., CONCISE ENCYCLOPEDIA OF POLYMER SCIENCEAND ENGINEERING 734-44, Plasticizers (1990), which is herebyincorporated by reference. In the case of triblock copolymers,lubrication of the endblocks should be avoided since the endblockdomains are responsible for holding the triblock copolymers together andimpart the material with strength (e.g., tensile strength duringelongation). Thus, a plasticizer which associates with the midblocks isexample. According to the lubricity theory, when manipulative force isexerted on the material, plasticizer 3910 facilitates movement ofmidblocks 3216 past each other. Id. at 734-35. The arrows in FIGS. 39b,39 c and 39 d represent the motion of midblocks 3216 with respect toeach other. FIG. 39b represents adjacent midblocks being pulled awayfrom each other. FIG. 39c represents two midblocks being forcedside-to-side. FIG. 39d represents adjacent midblocks being pulled acrossone another.

[0235]FIGS. 39e and 39 f depict a second plasticization theory, the geltheory, which reasons that the resistance of amorphous polymers todeformation results from an internal, three dimensional honeycombstructure or gel. Loose attachments between adjacent polymer chains,which occur at intervals along the chains, called attachment points,form the gel. Closer attachment between adjacent chains creates astiffer and more brittle material. Plasticizers 3910 break, or solvate,the points of attachment 3914 between polymer chains, loosening thestructure of the material. Thus, plasticizers produce about the sameeffect on a material as if there were fewer attachment points betweenpolymer chains, making the material softer or less brittle. See Id. at735. Since one of the purposes of the example gel is to provide amaterial which does not have significantly decreased tensile strength,which is provided by agglomeration of the endblocks, according to thegel theory plasticizer 3910 should associate with midblocks 3216 ratherthan with the endblocks. Further, a plasticizer which associates withthe midblock polymers decreases the attachment of adjacent midblocks,which likely decreases the rigidity while increasing the pliability,elongation and elasticity or visco-elasticity of the material. Similarto the lubricity theory, under the gel theory, reduction of attachmentpoints between adjacent midblocks facilitates movement of the midblockspast one another as force is applied to the material.

[0236] Referring now to FIG. 39g, the mechanistic theory ofplasticization assumes that different types of plasticizers 3910, 3912,etc. are attracted to polymer chains by forces of different magnitudes.In addition, the mechanistic theory supposes that, rather than attachpermanently, a plasticizer molecule attaches to a given attachment pointonly to be later dislodged and replaced by another plasticizer molecule.This continuous exchange of plasticizers 3910, 3912, etc., demonstratedby FIG. 39g as different stages connected by arrows which represent anequilibrium between each stage, is known as a dynamic equilibriumbetween solvation and desolvation of the attachment points betweenadjacent polymer chains. The number or fraction of attachment pointsaffected by a plasticizer depends upon various conditions, such asplasticizer concentration, temperature, and pressure. See Id.Accordingly, as applied to the example gel material, a large amount ofplasticizer would be necessary to affect the majority of midblockattachment points and thus provide the desired amounts of rigidity,softness, pliability, elongation and elasticity or visco-elasticity.

[0237] With reference to FIGS. 39h through 39 j, the fourthplasticization theory, known as the free volume theory, assumes thatthere is nothing but free space between molecules. As molecular motionincreases (e.g., due to heat), the free space between moleculesincreases. Thus, a disproportionate amount of that free volume isassociated with the ends of the polymer chains. As FIGS. 39h through 39j demonstrate, free volume is increased by using polymers with shorterchain lengths. For example, the black rectangles of FIG. 39h represent amaterial made up of long midblock polymers 3216. The white areas aroundeach black rectangle represent a constant width of free space around themolecule. In FIG. 39i, a molecule 3916, which is smaller than midblock3216, is added to the material, creating more free space. In FIG. 39j,an even smaller molecule 3918 has been added to the material. Theincrease in free space within the material is evident from the increasedarea of white space. The crux of the free volume theory is that theincrease in free space or volume allows the molecules to more easilymove past one another. In other words, the use of a small (or lowmolecular weight) plasticizer increases the ability of the midblockpolymer chains to move past each other. While FIGS. 39h, 39 i and 39 jprovide a fair representation of the free volume theory, in reality, theincrease in free space would be much greater than a two-dimensionaldrawing illustrates since molecules are three dimensional structures.

[0238] Similarly, the use of polymers with flexible side chains createadditional free volume around the molecule, which produces a similarplasticization-like effect, called internal plasticization. Applicantbelieves that incorporation of monomers into the midblock, which createflexible side chains thereon, including but not limited to isoprene(either hydrogenated or non-hydrogenated) and ethylene/propylenemonomers, creates internal plasticization. In compassion, the additionof an even smaller plasticizer molecule, described above, increases thefree space at a given location; this is external plasticization. Thesize and shape of plasticizing molecule and the nature of its atoms andgroups of atoms (i.e., nonpolar, polar, hydrogen bonding or not, anddense or light) determines the plasticizer's plasticizing ability on aspecific polymer. See Id.

[0239] With this general background in mind, Applicant will explain theformulation, chemical structure and performance of the example gelmaterial.

[0240] 2. Definitions

[0241] For the reader's convenience, Applicant has defined several termswhich are used throughout the description of the present gel.Additionally, other terms have been defined throughout the detaileddescription of the example gel material.

[0242] a. Elasticity and Visco-Elasticity

[0243] When finite strains are imposed upon visco-elastic materials,such as the example gel materials, the stress-strain relations are muchmore complicated than those ordinarily anticipated in accordance withthe classical theory of elasticity (Hooke's law) or the classical theoryof hydrodynamics (Newton's law). According to Hooke's law, stress isalways directly proportional to strain in small deformations butindependent of the rate of strain or the strain history. Newton's law ofhydrodynamics, which deals with the properties of viscous liquids,states that stress is always directly proportional to the rate of strainbut independent of the strain itself.

[0244] “Elastic,” as defined herein, refers to a characteristic ofmaterials which return substantially to their original shape followingdeformation and the subsequent cessation of deforming force.

[0245] “Visco-,” as defined herein, relates to both the rate ofdeformation and the rate of reformation. In reference to deformationrate, the faster a deforming force is applied to a visco elasticmaterial, the stiffer it is. The rate of reformation of a visco-elasticmaterial is slower than that of a truly elastic material.

[0246] Even if both strain and rate of strain are infinitesimal, avisco-elastic material may exhibit behavior that combines liquid-likeand solid-like characteristics. For example, materials that exhibitnot-quite-solid-like; characteristics do not maintain a constantdeformation under constant stress but deform, or creep, gradually overtime. Under constant deformation, the stress required to hold avisco-elastic material in the deformed state gradually diminishes untilit reaches a relatively steady state. On the other hand, a visco-elasticmaterial that exhibits not-quite-liquid like characteristics may, whileflowing under constant stress, store some of the energy input instead ofdissipating it all as heat. The stored energy may then cause thematerial to at least partially recover from its deformation, known aselastic recoil, when the stress is removed. When viscoelastic materialsare subjected to sinusoidally oscillating stress, the strain is neitherexactly in phase with the stress (as it would be for a perfectly elasticsolid) nor 90° out of phase (as it would be for a perfectly viscousliquid), but is somewhere in between. Visco-elastic materials store andrecover some of the deforming energy during each cycle, and dissipatesome of the energy as heat. If the strain and rate of strain on avisco-elastic material are infinitesimal, the behavior of that materialis linear viscoelastic and the ratio of stress to strain is a functionof time (or frequency) alone, not of stress magnitude. The gel materialexample is elastic in nature. Visco-elastic materials are also useful inthe cushions.

[0247] b. Rebound Rate

[0248] “Rebound rate”, as defined herein, is the amount of time it takesa one inch long piece of material to rebound to within about fivepercent its original shape and size following the release of stresswhich elongates the material to a length of two inches. The exampleelastic (or elastomeric) gel material useful in the cushioning elementshas a rebound rate of less than about one second. The examplevisco-elastic (or visco-elastomeric) gel material useful in thecushioning elements has a rebound rate of at least about one second.More preferably, the example visco-elastic gel has a rebound rate withinthe range of about one second to about ten minutes.

[0249] “Instantaneous Rebound,” as defined herein, refers to acharacteristic of a one inch long piece of an elastomeric material whichreturns substantially to its original size and shape in times of aboutone second or less following the release of stress which elongates thematerial to a length of two inches. “Elastomer,” as used herein, refersto the gel materials that are useful in the cushioning element hereofand which have instantaneous rebound.

[0250] “Delayed Rebound,” as used herein, refers to a characteristic ofthe visco-elastic materials example for use in the cushions hereof whichhave a rebound rate of at least about one second. More preferably, theexample visco-elastomeric material has a rebound rate within the rangeof about one second to about ten minutes. “Visco-elastomer,” as definedherein, refers to gel materials useful in the cushions which exhibitdelayed rebound characteristics.

[0251] c. Resins

[0252] The term “resin” is defined herein as a solid or semisolidfusible, organic substance that is usually transparent or translucent,is soluble in organic solvent but not in water, is an electricalnonconductor, and includes tackifiers. Resins are complex mixtures whichassociate together due to similar physical or chemical properties.Because of their complex nature, resins do not exhibit simple melting orboiling points.

[0253] “Resinous” as used herein refers to resins and resin-likematerials.

[0254] “Resinous plasticizers” as used herein refers to plasticizerswhich include a majority, by weight, of a resin or resins.

[0255] “Tackifier” as used herein refers to resins that add tack to theresulting mixture. The primary function of a tackifier is to add tack.The secondary functions of tackifiers include modification of both meltviscosity and melt temperature.

[0256] Tackifiers are normally low molecular weight and high glasstransition temperature (Tg) materials, and are sometimes characterizedas highly condensed acrylic structures. The most commonly usedtackifiers are rosin derivatives, terpene resins, and synthetic ornaturally derived petroleum resins. A tackifier's effectiveness islargely determined by its compatibility with the rubber component and byits ability to improve the tackiness of a material.

[0257] “Low molecular weight,” as defined herein with reference toresins, means resins having a weight average molecular weight of lessthan about 50,000.

[0258] Resins and tackifiers are used in some example formulations ofthe example gel cushioning medium.

[0259] d. Oils

[0260] The term “oil” is defined herein as naturally occurringhydrocarbon liquids, the carbons of which are primarily saturated withhydrogen atoms. Oils example for use in the example gel are mineraloils.

[0261] “Paraffinic” oils have include straight-chain or branched-chainstructures. “Naphthenic” oils include cyclic hydrocarbon structures.When an oil contains both paraffinic- and naphthenic-type structures,the relative concentrations of each type of structure determine whetherthe oil is identified as naphthenic or paraffinic.

[0262] “Oil viscosity” is defined herein as the measurement of time ittakes a given volume of oil to pass through an orifice, such as acapillary tube. Viscosity measurements include the Saybolt universalsecond (SUS), stokes (s) and centistokes (cs).

[0263] e. Molecular Weight

[0264] “Number Average Molecular Weight” (Mn), as determined by gelpermeation chromatography, provides information about the lowermolecular weight parts of a substance which includes hydrocarbonmolecules.

[0265] “Weight Average Molecular Weight” (MW), as determined by gelpermeation chromatography, indicates the average molecular weight ofhydrocarbon molecules in a substance. This is the value that is commonlyused in reference to the molecular weight of a hydrocarbon molecule.

[0266] “Z-Average Molecular Weight” (Mz), as determined by gelpermeation chromatography, is used as an indication of thehigh-molecular-weight portion of a substance which includes hydrocarbonmolecules. When the substance is a resin, the Z-average molecular weightindicates the compatibility and adhesive properties of that resin.

[0267] Molecular weight values may also be determined by any of severalother methods, such as the Flory viscosity method, the Staudingerviscosity method, light scattering in combination with high performanceliquid chromatography (HPLC, and others.

[0268] f. Cloud Point Tests

[0269] The following values, which are determined by cloud point tests,are useful in determining the compatibility of a resin with differenttypes of materials.

[0270] “MMAP,” as defined herein, is a measurement of aromaticsolubility and determines the aliphatic/aromatic character of a resin.The MMAP value is obtained by dissolving a resin in a high temperaturemixture of one part methylcyclohexane and two parts aniline, and coolingthe solution while mixing to determine the temperature at which themixture starts becoming cloudy, which is commonly referred to as thecloud point. The lower the MMAP value, the greater the aromaticity andlower the aliphaticity of the resin.

[0271] “DACP,” as defined herein, is a value which determines thepolarity of a resin due to the highly polar nature of the solventsystem. In order to determine the DACP value of resin, the resin mustfirst be dissolved in a heated 1:1 mixture of xylene and4-hydroxy-4-methyl-pentanone. The solution its then cooled with mixing.The temperature at which the solution begins becoming opaque is thecloud point, which is the DACP value.

[0272] Since specific adhesion is related to the polarity of a resin,the DACP value can be used as a specific adhesion indicator. Lower DACPvalues indicate greater specific adhesion.

[0273] “OMSCP,” as defined herein, is a value which is related to themolecular weight and molecular weight distribution of a resin. OMSCP candetermine the compatibility characteristics of a resin/polymer system.The higher the OMS cloud point, the greater the molecular weight and themolecular weight distribution of a resin. In particular, high OMSCPvalues can indicate the presence of high molecular weight materials (ofZ-average molecular weight).

[0274] The term “OMSCI'” is derived from the method for determiningOMSCP values. A resin is first dissolved in a high temperature mixtureof odorless mineral spirits (OMS). The solution is then cooled withmixing. The temperature at which the mixture starts becoming cloudy isreferred to as the cloud point (CP), or OMSCP value.

[0275] 3. Material Formulations

[0276] a. Elastomer Component

[0277] Preferably, the compositions of the example gel materials are lowdurometer (as defined below) thermoplastic elastomeric compounds andviscoelastomeric compounds which include a principle polymer component,an elastomeric block copolymer component and a plasticizer component.

[0278] The elastomer component of the example gel material includes atriblock polymer of the general configuration A-B-A, wherein the Arepresents a crystalline polymer such as a mono alkenylarene polymer,including but not limited to polystyrene and functionalized polystyrene,and the B is an elastomeric polymer such as polyethylene, polybutylene,poly(ethylene/butylene), hydrogenated poly(isoprene), hydrogenatedpoly(butadiene), hydrogenated poly(isoprene+butadiene),poly(ethylene/propylene) or hydrogenatedpoly(ethylene/butylene+ethylene/propylene), or others. The A componentsof the material link to each other to provide strength, while the Bcomponents provide elasticity. Polymers of greater molecular weight areachieved by combining many of the A components in the A portions of eachA-B-A structure and combining many of the B components in the B portionof the A-B-A structure, along with the networking of the A-B-A moleculesinto large polymer networks.

[0279] A example elastomer for making the example gel material is a veryhigh to ultra high molecular weight elastomer and oil compound having anextremely high Brookfield Viscosity (hereinafter referred to as“solution viscosity”). Solution viscosity is generally indicative ofmolecular weight. “Solution viscosity” is defined as the viscosity of asolid when dissolved in toluene at 25-30° C., measured in centipoises(cps). “Very high molecular weight” is defined herein in reference toelastomers having a solution viscosity, 20 weight percent solids in 80weight percent toluene, the weight percentages being based upon thetotal weight of the solution, from greater than about 20,000 cps toabout 50,000 cps. An “ultra high molecular weight elastomer” is definedherein as an elastomer having a solution viscosity, 20 weight percentsolids in 80 weight percent toluene, of greater than about 50,000 cps.Ultra high molecular weight elastomers have a solution viscosity, 10weight percent solids in 90 weight percent toluene, the weightpercentages being based upon the total weight of the solution, of about800 to about 30,000 cps and greater. The solution viscosities, in 80weight percent toluene, of the A-B-A block copolymers useful in theelastomer component of the example gel cushioning material aresubstantially greater than 30,000 cps. The solution viscosities, in 90weight percent toluene, of the example A-B-A elastomers useful in theelastomer component of the example gel are in the range of about 2,000cps to about 20,000 cps. Thus, the example elastomer component of theexample gel material has a very high to ultra high molecular weight.

[0280] Applicant has discovered that, after surpassing a certain optimummolecular weight range, some elastomers exhibit lower tensile strengththan similar materials with optimum molecular weight copolymers. Thus,merely increasing the molecular weight of the elastomer will not alwaysresult in increased tensile strength.

[0281] The elastomeric B portion of the example A-B-A polymers has anexceptional affinity for most plasticizing agents, including but notlimited to several types of oils, resins, and others. When the networkof A-B-A molecules is denatured, plasticizers which have an affinity forthe B block can readily associate: with the B blocks. Upon renaturationof the network of A-B-A molecules, the plasticizer remains highlyassociated with the B portions, reducing or even eliminating plasticizerbleed from the material when compared with similar materials in theprior art, even at very high oil:elastomer ratios. The reason for thisperformance may be any of the plasticization theories explained above(i.e., lubricity theory, gel theory, mechanistic theory, and free volumetheory).

[0282] The elastomer used in the example gel cushioning medium ispreferably an ultra high molecular weight polystyrene-hydrogenatedpoly(isoprene+butadiene)-polystyrene, such as those sold under the brandnames SEPTON 4045, SEPTON 4055 and SEPTON 4077 by Kuraray, an ultra highmolecular weight polystyrene-hydrogenated polyisoprene-polystyrene suchas the elastomers made by Kuraray and sold as SEPTON 2005 and SEPTON2006, or an ultra high molecular weight polystyrene-hydrogenatedpolybutadiene-polystyrene, such as that sold as SEPTON 8006 by Kuraray.High to very high molecular weight polystyrene-hydrogenatedpoly(isoprene+butadiene)-polystyrene elastomers, such as that sold underthe trade name SEPTON 4033 by Kuraray, are also useful in someformulations of the example gel material because they are easier toprocess than the example ultra high molecular weight elastomers due totheir effect on the melt viscosity of the material.

[0283] Following hydrogenation of the midblocks of each of SEPTON 4033,SEPTON 4045, SEPTON 4055, and SEPTON 4077, less than about five percentof the double bonds remain. Thus, substantially all of the double bondsare removed from the midblock by hydrogenation.

[0284] Applicant's most example elastomer for use in the example gel isSEPTON 4055 or another material that has similar chemical and physicalcharacteristics. SEPTON 4055 has the optimum molecular weight(approximately 300,000, as determined by Applicant's gel permeationchromatography testing). SEPTON 4077 has a somewhat higher molecularweight, and SEPTON 4045 has a somewhat lower molecular weight thanSEPTON 4055. Materials which include either SEPTON 4045 or SEPTON 4077as the primary block copolymer typically have lower tensile strengththan similar materials made with SEPTON 4055.

[0285] Kuraray Co. Ltd. of Tokyo, Japan has stated that the solutionviscosity of SEPTON 4055, the most example A-B-A triblock copolymer foruse in the example gel material, 10% solids in 90% toluene at 25° C., isabout 5,800 cps. Kuraray also said that the solution viscosity of SEPTON4055, 5% solids in 95% toluene at 25° C., is about 90 cps. AlthoughKuraray has not provided a solution viscosity, 20% solids in 80% tolueneat 25° C., an extrapolation of the two data points given shows that sucha solution viscosity would be about 400,000 cps. Applicant reads theprior art as consistently teaching away from such high solutionviscosities.

[0286] Applicant confirmed Kuraray's data by having an independentlaboratory, SGS U.S. Testing Company Inc. of Fairfield, N.J., test thesolution viscosity of SEPTON 4055. When SGS attempted to dissolve 20%solids in 80% toluene at 25° C., the resulting material did not resemblea solution. Therefore, SGS determined the solution viscosity of SEPTON4055 using 10% solids in 90% toluene at 25° C., which resulted in a3,040 cps solution.

[0287] Other materials with chemical and physical characteristicssimilar to those of SEPTON 4055 include other A-B-A triblock copolymerswhich have a hydrogenated midblock polymer that is made up of at leastabout 30% isoprene monomers and at least about 30% butadiene monomers,the percentages being based on the total number of monomers that make upthe midblock polymer. Similarly, other A-B-A triblock copolymers whichhave a hydrogenated midblock polymer that is made up of at least about30% ethylene/propylene monomers and at least about 30% ethyleneibutylenemonomers, the percentages being based on the total number of monomersthat make up the midblock polymer, are materials with chemical andphysical: characteristics similar to those of SEPTON 4055.

[0288] Mixtures of block copolymer elastomers are also useful as theelastomer component of some of the formulations of the example gelcushioning medium. In such mixtures, each type of block copolymercontributes different properties to the material. For example, highstrength triblock copolymer elastomers are desired to improve thetensile strength and durability of a material. However, some highstrength triblock copolymers are very difficult to process with someplasticizers. Thus, in such a case, block copolymer elastomers whichimprove the processability of the materials are desirable.

[0289] In particular, the process of compounding SEPTON 4055 withplasticizers may be improved via a lower melt viscosity by using a smallamount of more flowable elastomer such as SEPTON 8006, SEPTON 2005,SEPTON 2006, or SEPTON 4033, to name only a few, without significantlychanging the physical characteristics of the material.

[0290] In a second example of the usefulness of block copolymerelastomer mixtures in the example gel materials, many block copolymersare not good compatibilizers. Other block copolymers readily formcompatible mixtures, but have other undesirable properties. Thus, theuse of small amount of elastomers which improve the uniformity withwhich a material mixes are desired. KRATONO G 1701, manufactured byShell Chemical Company of Houston, Tex., is one such elastomer thatimproves the uniformity with which the components of the example gelmaterial mix.

[0291] Many other elastomers, including but not limited to triblockcopolymers and diblock copolymers are also useful in the example gelmaterial. Applicant believes that elastomers having a significantlyhigher molecular weight than the ultra-high molecular weight elastomersuseful in the example gel material increase the softness thereof, butdecrease the strength of the gel. Thus, high to ultra high molecularweight elastomers, as defined above, are desired for use in the examplegel material due to the strength of such elastomers when combined with aplasticizer.

[0292] b. Additives

[0293] i. Polarizable Plasticizer Bleed-Reducing Additives 65

[0294] Preferably, the gel materials used in the cushions do not exhibitmigration of plasticizers, even when placed against materials whichreadily exhibit a high degree of capillary action, such as paper, atroom temperature.

[0295] A example plasticizer bleed-reducing additive that is useful inthe example gel cushioning material includes hydrocarbon chains withreadily polarizable groups thereon. Such polarizable groups include,without limitation, halogenated hydrocarbon groups, halogens, nitriles,and others. Applicant believes that the polarizability of such groups onthe hydrocarbon molecule of the bleed-reducing additive have a tendencyto form weak van der Waals bonding with the long hydrocarbon chains ofthe rubber portion of an elastomer and with the plasticizer molecules.Due to the great length of typical rubber polymers, several of thebleed-reducers will be attracted thereto, while fewer will be attractedto each plasticizer molecule. The bleed-reducing additives are believedto hold the plasticizer molecules and the elastomer molecules thereto,facilitating attraction between the elastomeric block and theplasticizer molecule. In other words, the example bleed-reducingadditives are believed to attract a plasticizer molecule at onepolarizable site, while attracting an elastomeric block at anotherpolarizable site, thus maintaining the association of the plasticizermolecules with the elastomer molecules, which inhibits exudation of theplasticizer molecules from the elastomer-plasticizer compound. Thus,each of the plasticizer molecules is preferably attracted to anelastomeric block by means of a bleed-reducing additive.

[0296] The example bleed-reducing additives that are useful in theexample gel material have a plurality of polarizable groups thereon,which facilitate bonding an additive molecule to a plurality ofelastomer molecules and/or plasticizer molecules. It is believed that anadditive molecule with more polarizable sites thereon will bond to moreplasticizer molecules. Preferably, the additive molecules remain in aliquid or a solid state during processing of the gel material.

[0297] The most example bleed-reducing additives for use in the examplegel material are halogenated hydrocarbon additives such as those soldunder the trade name DYNAMAR™ PPA 791, DYNAMAR™ PPA-790, DYNAMAR™FX-9613, and FLUORAD® FC 10 Fluorochemical Alcohol, each by 3M Companyof St. Paul, Minn. Other additives are also useful to reduce plasticizerexudation from the example gel material. Such additives include, withoutlimitation, other halogenated hydrocarbons sold under the trade nameFLUORAD®, including without limitation FC-129, FC-135, FC-430, FC-722,FC-724, FC-740, FX-8, FX-13, FX-14 and FX-189; halogentated hydrocarbonssuch as those sold under the trade name ZONYL®, including withoutlimitation FSN 100, FSO 100, PFBE, 8857A, TM, BA-L, BA-N, TBC and FTS,each of which are manufactured by du Pont of Wilmington, Del.;halogenated hydrocarbons, sold under the trade name EMCOL by Witco Corpof Houston, Tex., including without limitation 4500 and DOSS; otherhalogenated hydrocarbons sold by 3M under the trade name DYNAMA.RTM;chlorinated polyethylene elastomer (CPE), distributed by Harwick, Inc.of Akron, Ohio; chlorinated paraffin wax, distributed by Harwick, Inc.;and others.

[0298] ii. Detackifiers

[0299] The example material may include a detackifier. Tack is not adesirable feature in many potential uses for the cushions. However, someof the elastomeric copolymers and plasticizers useful in the examplecushioning media for the cushioning elements may impart tack to themedia.

[0300] Soaps, detergents and other surfactants have detackifyingabilities and are useful in the example gel material. “Surfactants,” asdefined herein, refers to soluble surface active agents which containgroups that have opposite polarity and solubilizing tendencies.Surfactants form a monolayer at interfaces between hydrophobic andhydrophilic phases; when not located at a phase interface, surfactantsform micelles. Surfactants have detergency, foaming, wetting,emulsifying and dispersing properties. Sharp, D. W. A., DICTIONARY ofCHEMISTRY, 381-82 (Penguin, 1990). For example, coco diethanolamide, acommon ingredient in shampoos, is useful in the example gel material asa detackifying agent. Coco diethanolamide resists evaporation, isstable, relatively non-toxic, non-flammable and does not supportmicrobial growth. Many different soap or detergent compositions could beused in the material as well.

[0301] Other known detackifiers include glycerin, epoxidized soybeanoil, dimethicone, tributyl phosphate, block copolymer polyether,diethylene glycol mono oleate, tetraethyleneglycol dimethyl ether, andsilicone, to name only a few. Glycerine is available from a wide varietyof sources. Witco Corp. of Greenwich, Connecticut sells epoxidizedsoybean oil as DRAPEX 6.8. Dimethicone is available from a variety ofvendors, including GE Specialty Chemicals of Parkersburg, W. Va. underthe trade name GE SF 96-350. C. P. Hall Co. of Chicago, Ill. marketsblock copolymer polyether as PLURONIC L-61. C. P. Hall Co. alsomanufactures and markets diethylene glycol mono oleate under the nameDiglycol Oleate Hallco CPH-1-SE. Other emulsifiers and dispersants arealso useful in the example gel material. Tetraethyleneglycol dimethylether is available under the trade name TETRAGLYME from FerroCorporation of Zachary, Louisiana. Applicant believes that TETRAGLYMEalso reduces plasticizer exudation from the example gel material.

[0302] iii. Antioxidants

[0303] The example gel material also includes additives such as anantioxidant. Antioxidants such as those sold under the trade namesIRGANOX® 1010 and IRGAFOS® 168 by Ciba-Geigy Corp. of Tarrytown, N.Y.are useful by themselves or in combination with other antioxidants inthe example materials.

[0304] Antioxidants protect the example gel materials against thermaldegradation during processing, which requires or generates heat. Inaddition, antioxidants provide long term protection from free radicals.A example antioxidant inhibits thermo-oxidative degradation of thecompound or material to which it is added, providing long termresistance to polymer degradation. Preferably, an antioxidant added tothe example gel cushioning medium is useful in food packagingapplications, subject to the provisions of 21 C.F.R. § 178.2010 andother laws.

[0305] Heat, light (in the form of high energy radiation), mechanicalstress, catalyst residues, and reaction of a material with impuritiesall cause oxidation of the material. In the process of oxidation, highlyreactive molecules known as free radicals are formed and react in thepresence of oxygen to form peroxy free radicals, which further reactwith organic material (hydro-carbon molecules) to form hydroperoxides.

[0306] The two major classes of antioxidants are the primaryantioxidants and the secondary antioxidants. Peroxy free radicals aremore likely to react with primary antioxidants than with most otherhydrocarbons. In the absence of a primary antioxidant, a peroxy freeradical would break a hydrocarbon chain. Thus, primary antioxidantsdeactivate a peroxy free radical before it has a chance to attack andoxidize an organic material.

[0307] Most primary antioxidants are known as sterically hinderedphenols. One example of sterically hindered phenol is the C₇₃H108,012marketed by Ciba-Geigy as IRGANOX® 1010, which has the chemical name3,5-bis(1,1-dimethylethyl)-4-hydroxybenzenepropanoic acid,2,2-bis[[3-[3,5-bis(dimethyletllyl)-4-hydroxyphenyl]-1-oxopropoxy]methyl]1,3-propanediylester. The FDA refers to IRGANOX® 1010 astetrakis[methylene(3,5-di-tert-butyl-4-hydroxyhydrocinnimate)]methane.Other hindered phenols are also useful as primary antioxidants in theexample material.

[0308] Similarly, secondary antioxidants react more rapidly withhydroperoxides than most other hydrocarbon molecules. Secondaryantioxidants have been referred to as hydroperoxide decomposers. Thus,secondary antioxidants protect organic materials from oxidativedegradation by hydroperoxides.

[0309] Commonly used secondary antioxidants include the chemical classesof phosphites/phosphonites and thioesters, many of which are useful inthe example gel material. The hydroperoxide decomposer used by Applicantis a CQZH6,03P phosphite known as Tris(2,4 di-tert-butylphenyl)phosphiteand marketed by Ciba-Geigy as IRGAFOS® 168.

[0310] It is known in the art that primary and secondary antioxidantsform synergistic combinations to ward off attacks from both peroxy freeradicals and hydroperoxides.

[0311] Other antioxidants, including but not limited to multi-functionalantioxidants, are also useful in the example material. Multifunctionalantioxidants have the reactivity of both a primary and a secondaryantioxidant. IRGANOX® 1520 D, manufactured by Ciba-Geigy is one exampleof a multifunctional antioxidant. Vitamin E antioxidants, such as thatsold by CibaGeigy as IRGANOX® E17, are also useful in the examplecushioning material for use in the cushions.

[0312] Preferably, the example gel material includes up to about threeweight percent antioxidant, based on the weight of the elastomercomponent, when only one type of antioxidant is used. The material mayinclude as little as 0.1 weight percent of an antioxidant, or noantioxidant at all. When a combination of antioxidants is used, each maycomprise up to about three weight percent, based on the weight of theelastomer component. Additional antioxidants may be added for severeprocessing conditions involving excessive heat or long duration at ahigh temperature.

[0313] Applicant believes that the use of excess antioxidants reduces oreliminates tack on the exterior surface of the example gel material.Excess antioxidants appear to migrate to the exterior surface of thematerial following compounding of the material. Such apparent migrationoccurs over substantial periods of time, from hours to days or evenlonger.

[0314] iv. Flame Retardants

[0315] Flame retardants may also be added to the example gel materials.Flame retardants useful in the cushioning elements include but are notlimited to diatomaceous earth flame retardants sold as GREAT LAKES DE83R and GREAT LAKES DE 79 by Great Lakes Filter, Division of Acme MillsCo. of Detroit, Mich. Most flame retardants that are useful inelastomeric materials are also useful in the example gel material. Inparticular, Applicant prefers the use of food grade flame retardantswhich do not significantly diminish the physical properties of theexample gel material.

[0316] Chemical blowing agents, such as SAFOAM® FP-40, manufactured byReedy International Corporation of Keyport, N.J. and others are usefulfor making a gel cushioning medium that is self-extinguishing.

[0317] v. Colorants

[0318] Colorants may also be used in the example gel materials for usein the cushions. Any colorant which is compatible with elastomericmaterials may be used in the materials. In particular, Applicant prefersto use aluminum lake colorants such as those manufactured by WarnerJenkinson Corp. of St. Louis, Mo.; pigments manufactured by Day GloColor Corp. of Cleveland, Ohio; Lamp Black, such as that sold bySpectrum Chemical Manufacturing Corp. of Gardena, Calif.; and TitaniumDioxide (white). By using these colorants, the gel material takes onintense shades of colors, including but not limited to pink, red,orange, yellow, green, blue, violet, brown, flesh, white and black.

[0319] vi. Paint

[0320] The example gel cushioning medium may also be painted.

[0321] vii. Other Additives

[0322] Other additives may also be added to the example gel material.Additives such as foaming facilitators, tack modifiers, plasticizerbleed modifiers, flame retardants, melt viscosity modifiers, melttemperature modifiers, tensile strength modifiers, and shrinkageinhibitors are useful in specific formulations of the example gelmaterial.

[0323] Melt temperature modifiers useful in the example gel includecross-linking agents, hydrocarbon resins, diblock copolymers of thegeneral configuration A-B and triblock copolymers of the generalconfiguration A-B-A wherein the end block A polymers includefunctionalized styrene monomers, and others.

[0324] Tack modifiers which tend to reduce tack and which are useful inthe example gel include surfactants, dispersants, emulsifiers, andothers. Tack modifiers which tend to increase the tack of the materialand which are useful in the material include hydrocarbon resins,polyisobutylene, butyl rubber and others.

[0325] Foam facilitators that are useful in the gel material includepolyisobutylene, butyl rubber, surfactants, emulsifiers, dispersants andothers.

[0326] Plasticizer bleed modifiers which tend to reduce plasticizerexudation from the example material and which are useful therein includehydrocarbon resins, elastomeric diblock copolymers, polyisobutylene,butyl rubber, transpolyoctenylene rubber (“tor rubber”), and others.

[0327] Flame retardants useful in the example gel include halogenatedflame retardants, non-halogenated flame retardants, and volatile,non-oxygen gas forming chemicals and compounds.

[0328] Melt viscosity modifiers that tend to reduce the melt viscosityof the pre-compounded component mixture of the example cushioning mediuminclude hydrocarbon resins, transpolyoctenylene rubber, castor oil,linseed oil, non-ultra high molecular weight thermoplastic rubbers,surfactants, dispersants, emulsifiers, and others.

[0329] Melt viscosity modifiers that tend to increase the melt viscosityof the pre-compounded component mixture of the example gel materialinclude hydrocarbon resins, butyl rubber, polyisobutylene, additionaltriblock copolymers having the general configuration A-B-A and amolecular weight greater than that of each of the block copolymers inthe elastomeric block copolymer component of the material, particulatefillers, microspheres, butadiene rubber, ethylene/propylene rubber,ethylene/butylene rubber, and others.

[0330] Tensile strength modifiers which tend to increase the tensilestrength of the example gel material for use in the cushions include midblock B-associating hydrocarbon resins, non-end-block solvatinghydrocarbon resins which associate with the end blocks, particulatereinforcers, and others.

[0331] Shrinkage inhibitors, which tend to reduce shrinkage of the gelmaterial following compounding, that are useful in the material includehydrocarbon resins, particulate fillers, microspheres,transpolyoctenylene rubber, and others.

[0332] c. Microspheres

[0333] Microspheres may also be added to the example gel material. Thegel material may contain up to about 90% microspheres, by volume. In oneexample microsphere-containing formulation of the example gel material,microspheres make up at least about 30% of the total volume of thematerial. A second example microsphere-containing formulation of theexample gel cushioning medium includes at least about 50% microspheres,by volume.

[0334] Different types of microspheres contribute various properties tothe material. For example, hollow acrylic microspheres, such as thosemarketed under the brand name MICROPEARL, and generally in the 20 to 200micron size range, by Matsumoto Yushi-Seiyaku Co., Ltd. of Osaka, Japan,lower the specific gravity of the material. In other formulations of thegel, the microspheres may be unexpanded DU(091-80), which expand duringprocessing of the example gel cushioning medium, or pre-expanded DE(091-80) acrylic microspheres from Expancel Inc. of Duluth, Ga.

[0335] In formulations of the example material which include hollowacrylic microspheres, the microspheres preferably have substantiallyinstantaneous rebound when subjected to a compression force whichcompresses the microspheres to a thickness of up to about 50% of theiroriginal diameter or less.

[0336] Hollow microspheres also decrease the specific gravity of the gelmaterial by creating gas pockets therein. In many cushioningapplications, very low specific gravities are example. The specificgravity of the example gel cushioning medium may range from about 0.06to about 1.30, depending in part upon the amount and specific gravity offillers and additives, including microspheres and foaming agents. Inmany cushioning applications, a gel material having a specific gravityof less than about 0.50 is example. When a gel material example for usein cushions includes the example microspheres, the microspheres must bedispersed, on average, at a distance of about one-and-a half (1.5) timesthe average microsphere diameter or a lesser distance from one anotherin order to achieve a specific gravity of less than about 0.50. Aspecific gravity of less than about 0.30 is example for use in somecushions. Other formulations of the example gel material have specificgravities of less than about 0.65, less than about 0.45, and less thanabout 0.25.

[0337] MICROPEARL and EXPANCEL acrylic microspheres are example becauseof their highly flexible nature, as explained above, which tend to notrestrict deformation of the thermoplastic elastomer. Glass, ceramic, andother types of microspheres may also be used in the thermoplastic gelmaterial, but are less example.

[0338] d. Plasticizer Component

[0339] As explained above, plasticizers allow the midblocks of a networkof triblock copolymer molecules to move past one, another. Thus,Applicant believes that plasticizers, when trapped within the threedimensional web of triblock copolymer molecules, facilitate thedisentanglement and elongation of the elastomeric midblocks as a load isplaced on the network. Similarly, Applicant believes that plasticizersfacilitate recontraction of the elastomeric midblocks following releaseof the load. The plasticizer component of the example gel cushioningmedium may include oil, resin, a mixture of oils, a mixture of resins,other lubricating materials, or any combination of the foregoing.

[0340] i. Oils

[0341] The plasticizer component of the example gel material may includea commercially available oil or mixture of oils. The plasticizercomponent may include other plasticizing agents, such as liquidoligomers and others, as well. Both naturally derived and synthetic oilsare useful in the example gel material. Preferably, the oils have aviscosity of about 70 SUS to about 500 SUS at about 100° F. Most examplefor use in the gel material are paraffinic white mineral oils having aviscosity in the range of about 90 SUS to about 200 SUS at about 100° F.

[0342] One embodiment of a plasticizer component of the example gelincludes paraffinic white mineral oils, such as those having the brandname DUOPRIME, by Lyondell Lubricants of Houston, Tex., and the oilssold under the brand name TUFFLO by Witco Corporation of Petrolia, Pa.For example, the plasticizer component of the example gel may includeparaffinic white mineral oil such as that sold under the trade nameLP-150 by Witco.

[0343] Paraffinic white mineral oils having an average viscosity ofabout 90 SUS, such as DUOPRIME 90, are example for use in otherembodiments of the plasticizer component of the example gel cushioningmedium. Applicant has found that DUOPRIME 90 and oils with similarphysical properties can be used to impart the greatest strength to theexample gel 9 material.

[0344] Other oils are also useful as plasticizers in compounding the gelmaterial. Examples of representative commercially available oils includeprocessing oils such as paraffinic and naphthenic petroleum oils, highlyrefined aromatic-free or low aromaticity paraffinic and naphthenic foodand technical grade white petroleum mineral oils, and synthetic liquidoligomers of polybutene, polypropene, polyterpene, etc., and others. Thesynthetic series process oils are oligomers which are permanently fluidliquid non-olefins, isoparaffrns or paraffrns. Many such oils are knownand commercially available. Examples of representative commerciallyavailable oils include Amoco® polybutenes, hydrogenated polybutenes andpolybutenes with epoxide functionality at one end of the polybutenepolymer. Examples of such Amoco polybutenes include: L-14 (320 Mn), L-50(420 Mn), L-100 (460 Mn), H-15 (560 Mn), H-25 Mn), H-35 (660 Mn), H-50(750 Mn), 13-100 (920 Mn), H-300 (1290 Mn, L-14E (27-37 cst @ 100° F.Viscosity), L-300E (635-6'90 cst @ 210° F. Viscosity), Actipol E6 (365Mn), E16 (973 Mn), E23 (1433 Mn) and the like. Examples of variouscommercially available oils include: Bayol, Bernol, American, Blandol,Drakeol, Ervol, Gloria, Kaydol, Litetek, Marcol, Parol, Peneteck, Pnmol,Protol, Sontex, and the like.

[0345] ii. Resins

[0346] Resins useful in the plasticizer component of the example gelmaterial include, but are not limited to, hydrocarbon-derived androsin-derived resins having a ring and ball softening point of up toabout 150° C., more preferably from about 0° C. to about 25° C., and aweight average molecular weight of at least about 300.

[0347] For use in many of the cushions, the use of resins or resinmixtures which are highly viscous flowable liquids at room temperature(about 23° C.) may be employed. Plasticizers which are fluid at roomtemperature impart softness to the gel material. Although roomtemperature flowable resins are example, resins which are not flowableliquids at room temperature are also useful in the material.

[0348] The resins most example for use in the example gel material havea ring and ball softening point of about 18° C.; melt viscosities ofabout 10 poises (ps) at about 61° C., about 100 ps at about 42° C. andabout 1,000 ps at about 32° C.; an onset Tg of about −20° C.; a MMAPvalue of 68° C.; a DACP value oi' 15° C.; an OMSCP value of less than−40° C.; a Mn of about 385; a Mw, of about 421; and a MZ of about 463.One such resin is marketed as REGALREZ© 1018 by Hercules Incorporated ofWilmington, Del. Variations of REGALREZ® 1018 which are useful in theexample cushioning material have viscosities including, but not limitedto, 1025 stokes, 1018 stokes, 745 stokes, 114 stokes, and others.

[0349] Room temperature flowable resins that are derived frompoly-β-pinene and have softening points similar to that of REGALREZ®1018 are also useful in the plasticizer component of the examplecushioning medium. One such resin, sold as PICCOLYTE® S25 by HerculesIncorporated, has a softening point of about 25° C.; melt viscosities ofabout 10 ps at about 80° C., about 100 ps at about 56° C. and about1,000 ps at about 41° C.; a MMAP value of about 88° C.; a DACP value ofabout 45° C.; an OMSCP value of less than about −50° C.; a MZ of about4,800; a Mw of about 1,950; and a Mn of about 650. Other PICCOLYTE®resins may also be used in the example gel material.

[0350] Another room temperature flowable resin which is useful in theplasticizer component of the example material is marketed as ADTAC® LVby Hercules Incorporated. That resin has a ring and ball softening pointof about 5° C.; melt viscosities of about 10 ps at about 62° C., about100 ps at about 36° C. and about 1,000 ps at about 20° C.; a MMAP valueof about 93° C.; a DACP value of about 44° C.; an OMSCP value of lessthan about −40° C.; a MZ of about 2,600; a Mw of about 1,380; and a Mnof about 800.

[0351] Resins such as the: liquid aliphatic C-5 petroleum hydrocarbonresin sold as WINGTACK® 10 by the Goodyear Tire & Rubber Company ofAkron, Ohio and other WINGTACK® resins are: also useful in the gelmaterial. WINGTACK® 10 has a ring and ball softening point of about 1.0°C.; a Brookfield Viscosity of about 30,000 cps at about 25° C.; meltviscosities of about 10 ps at about 53° C. and about 100 ps at about 34°C.; an onset Tg of about −37.7° C.; a Mn of about 660; a Mw of about800; a 1:1 polyethylene-to-resin ratio cloud point of about 89° C.; a1:1 microcrystalline wax-to-resin ratio cloud point of about 77° C.; anda 1:179 paraffin wax-to-resin ratio cloud point of about 64° C.

[0352] Resins that are not readily flowable at room temperature (i.e.,are solid, semi-solid, or have an extremely high viscosity) or that aresolid at room temperature are also useful in the example gel material.One such solid resin is an aliphatic C-5 petroleum hydrocarbon resinhaving a ring and ball softening point of about 98° C.; melt viscositiesof about 100 ps at about 156° C. and about 1000 ps at about 109° C.; anonset Tg of about 46.1° C.; a Mn of about 1,130; a MW of about 1,800; a1:1 polyethylene-to-resin ratio cloud point of about 90° C.; a 1:1microcrystalline wax-to-resin ratio cloud point of about 77° C.; and a1:1 paraffin wax-to-resin ratio cloud point of about, 64° C. Such aresin is available as WINGTACK® 95 and is manufactured by GoodyearChemical Co.

[0353] Polyisobutylene polymers are an example of resins which are notreadily flowable at room temperature and that are useful in the examplegel material. One such resin, sold as VISTANEX® LM-MS by Exxon ChemicalCompany of Houston, Tex., has a Tg of −60° C., a Brookfield Viscosity ofabout 250 cps to about 350 cps at about 350° F., a Flory molecularweight in the range of about 42,600 to about 46,100, and a Staudingermolecular weight in the range of about 10,400 to about 10,900. The Floryand Staudinger methods for determining molecular weight are based on theintrinsic viscosity of a material dissolved in diisobutylene at 1820° C.

[0354] Glycerol esters of polymerized rosin are also useful asplasticizers in the example gel material. One such ester, manufacturedand sold by Hercules Incorporated as HERCULES® Ester Gum I OD SyntheticResin, has a softening point of about 116° C.

[0355] Many other resins are also suitable for use in the gel material.In general, plasticizing resins are example which are compatible withthe B block of the elastomer used in the material, and non-compatiblewith the A blocks.

[0356] In some embodiments of the cushion, tacky materials may bedesirable. In such embodiments, the plasticizer component of the gelmaterial may include about 20 weight percent or more, about 40 weightpercent or more, about 60 weight percent or more, or up to about 100weight percent, based upon the weight of the plasticizer component, of atackifier or tackifier mixture.

[0357] iii. Plasticizer Mixtures

[0358] The use of plasticizer mixtures in the plasticizer component ofthe example gel material is useful for tailoring the physicalcharacteristics of the example gel material. For example,characteristics such as durometer, tack, tensile strengths elongation,melt flow and others may be modified by combining various plasticizers.

[0359] For example, a plasticizer mixture which includes at least about37.5 weight percent of a paraffinic white mineral oil having physicalcharacteristics similar to those of LP-150 (a viscosity of about 150 SUSat about 100° F., a viscosity of about 30 centistokes (cSt) at about 40°C., and maximum pour point of about −35° F.) and up to about 62.5 weightpercent of a resin having physical characteristics similar to those ofREGALREZO 1018 (such as a softening point of about 20° C.; an onset T9of about −20° C.; a MMAP value of about 70° C.; a DACP value of about15° C.; an OMSCP value of less than about −40° C.; and M, of about 400),all weight percentages being based upon the total weight of theplasticizer mixture, could be used in a gel cushioning medium. Whencompared to a material plasticized with the same amount of an oil suchas LP-150, the material which includes the plasticizer mixture hasdecreased oil bleed and increased tack.

[0360] Applicant believes that, when resin is included with oil in aplasticizer mixture of the example gel for use in cushions, the materialexhibits reduced oil bleed. For example, a formulation of the materialwhich includes a plasticizing component which has about three partsplasticizing oil (such as LP-150), and about five parts plasticizingresin (such as REGALREZ8 1018) exhibits infinitesimal oil bleed at roomtemperature, if any, even when placed against materials with highcapillary action, such as paper. Prior art thermoplastic elastomersbleed noticeably under these circumstances.

[0361] The plasticizer:block copolymer elastomer ratio, by totalcombined weight of the plasticizer component and the block copolymerelastomer component, of the example gel cushioning material for use inthe cushions ranges from as low as about 1:1 or less to higher thanabout 25:1. In applications where plasticizer bleed is acceptable, theratio may as high as about 100:1 or more. Especially example areplasticizer:block copolymer ratios in the range of about 2.5:1 to about8:1. A example ratio, such as 5:1 provides the desired amounts ofrigidity, elasticity and strength for many typical applications. Anotherexample plasticizer to block copolymer elastomer ratio of the examplegel material is 2.5:1, which has an unexpectedly high amount of strengthand elongation.

[0362] 4. Compounding Methods

[0363] As used herein, the term “liquification” refers to the placementof the block copolymer elastomer and plasticizer components of theexample gel cushioning medium in a liquid state, such as a molten stateor a dissolved state.

[0364] a. Melt Blending

[0365] A example method for manufacturing the example gel materialincludes mixing the plasticizer, block copolymer elastomer and anyadditives and/or fillers (e.g., microspheres), heating the mixture tomelting while agitating the mixture, and cooling the compound. Thisprocess is referred to as “melt blending.”

[0366] Excessive heat is known to cause the degradation of theelastomeric B portion of A-B-A and A-B block copolymers which are theexample elastomer component of the example gel material for use in thecushions. Similarly, maintaining block copolymers at increasedtemperatures over prolonged periods of time often results in thedegradation of the elastomeric B portion of A-B-A and A-B blockcopolymers. As the B molecules of an A-B-A triblock copolymer break, thetriblock is separated into two diblock copolymers having the generalconfiguration A-B. While it is believed by some in the art that thepresence of A-B diblock copolymers in oil-containingplasticizer-extended A-B-A triblock copolymers reduces plasticizerbleed-out, high amounts of A-B copolymers significantly reduce thestrength of the example gel material. Thus, Applicant believes that itis important to minimize the compounding temperatures and the amount oftime to which the material is exposed to heat.

[0367] The plasticizers, any additives and/or fillers, and the A-B-Acopolymers are premixed. Preferably, if possible, hydrophobic additivesare dissolved into the plasticizer prior to adding the plasticizercomponent to the elastomer component. If possible, hydrophilic additivesand particulate additives are preferably emulsified or mixed into theplasticizer of a example gel material prior to adding the elastomercomponents. The mixture is then quickly heated to melting. Preferably,the temperature of the mixture does not exceed the volatilizationtemperature of any component. For some of the example gel materials,Applicant prefers temperatures in the range of about 270° F. to about290° F. For other gel materials, Applicant prefers temperatures in therange of about 360° F. to about 400° F. A melting time of about tenminutes or less is example. A melting time of about five minutes or lessis more example. Even more example are melting times of about ninetyseconds or less. Stirring, agitation, or, most preferably, high shearingforces are example to create a homogeneous mixture. The mixture is thencast, extruded, injection molded, etc.

[0368] Next, the mixture is cooled. When injection molding equipment andcast molds are used, the mixture may be cooled by running coolantthrough the mold, by the thermal mass of the mold itself, by roomtemperature, by a combination of the above methods, or other methods.Extruded mixtures are cooled by air or by passing the extruded mixturethrough coolant. Cooling times of about five minutes or less areexample. A cooling time of less than one minute is most example.

[0369] Use of high shear facilitates short heating times. “High shear”,for purposes of this disclosure, is defined in terms of the length overdiameter (L/D) ratio of a properly designed injection molding singlescrew or extruder single screw. L/D ratios of about 20:1 and highercreate high shear. Twin screws, Banbury mixers and the like also createhigh shear. High shearing with heat mixes compounds at lowertemperatures and faster rates than the use of heat alone or heat withrelatively low-shear mixing. Thus, high shear forces expeditecompounding of the mixture over a relatively short period of time bymore readily forcing the molecules into close association with the 13component of the A-B-A copolymer. Use of high shear also facilitates thedecrease of equipment temperatures. Melt blending techniques whichemploy little or no shear require an external heat source. Thus, inorder to avoid heat loss, the periphery of many types of melt blendingequipment must be heated to a temperature higher than the melttemperature in order to transfer heat and melt a component mixture. Incomparison, high shearing equipment can generate high materialtemperatures directly from the shear forces, substantially reducing oreliminating the need for external heating.

[0370] The use of equipment that produces high shear, such as twin screwcompounding extrusion machinery, to melt blend the example gelcushioning medium can be employed. Twin screw extruders such as the ZE25TIEBAR AIR COOLED TWIN SCREW EXTRUDER, with a 35:1 L/D ratio,manufactured by Berstorff Corporation of Charlotte, N.C., are useful forcompounding the example gel material. Twin screw compounding extrusionmachinery is desired for compounding the example gel material since itgenerates a very high level of shear and because compounding andmolding, casting, extrusion, or foaming are performed in one continuousprocess. Alternatively, the example thermoplastic elastomeric may becompounded first, then later formed into a finished product by injectionmolding, extrusion, or some other 20 method.

[0371] It was mentioned above that microspheres may be added to the gelmaterial to reduce its specific gravity and to increase its stiffness ordurometer. Applicant has unexpectedly discovered that acrylicmicrospheres remain intact when subjected to the heat and shear ofinjection molding machines and extruders if the time at high temperatureis kept to about five minutes or less.

[0372] Other equipment, such as batch mixers are also useful for meltblending the example gel materials for use in the cushions.

[0373] b. Solvent Blending

[0374] A second example method for making the example elastomericcompounds comprises dissolving the elastomeric component in a solvent,adding the plasticizer component and any additives and/or fillers, andremoving the solvent from the mixture.

[0375] Aromatic hydrocarbon solvents such as toluene may be used formixing the example gel compounds. Sufficient solvent is added to theelastomer component to dissolve the network of block copolymermolecules. Preferably, the amount of solvent is limited to an amountsufficient for dissolving the network: of block copolymer molecules. Theelastomers then dissolve in the solvent. Mixing is example since itspeeds up the solvation process. Similarly, slightly elevating themixture temperature is example since it speeds up the solvation process.Next, plasticizer, any additives and any fillers are mixed into thesolvated elastomer. If possible, hydrophobic additives are preferablydissolved in the plasticizer prior to adding the plasticizer to theprinciple polymer, the block copolymer elastomer and the solvent.Preferably, if possible, hydrophilic additives and particulate additivesare emulsified or mixed into the plasticizer prior to adding theelastomer components and solvent. The mixture is then cast into adesired shape (accounting for later shrinkage due to solvent loss) andthe solvent is evaporated from the mixture.

[0376] Other methods of compounding the example materials, including butnot limited to other processes for compounding, modifying and extendingelastomeric materials, are also useful for compounding the example gelcushioning medium.

[0377] c. Foaming

[0378] The example gel material may be foamed. “Foaming”, as definedherein, refers to processes which form gas bubbles or gas pockets in thematerial. A example foamed gel material that is useful in the cushionshereof includes gas bubbles dispersed throughout the material. Both opencell and closed cell foaming are useful in the example gel material.Foaming decreases the specific gravity of the example material. In manycushioning applications, very low specific gravities are example. Thespecific gravity of the gel material may range, after foaming, fromabout 0.06 to about 1.30.

[0379] A example foamed formulation of the gel material includes atleast about 10% gas bubbles or gas pockets, by volume of the material.More preferably, when the material is foamed, gas bubbles or gas pocketsmake up at least about 20% of the volume of the material. Other foamedformulations of the example gel material contain at least about 40% gasbubbles or gas pockets, by volume, and at least about 70% gas bubbles orpockets, by volume. Various methods for foaming the example gel materialinclude, but are not limited to, whipping or injecting air bubbles intothe material while it is in a molten state, adding compressed gas or airto the material while it is in the molten state and under pressure,adding water to the material while it is in the molten state, use ofsodium bicarbonate, and use of chemical blowing agents such as thosemarketed under the brand name SAFOAM© by Reedy International Corporationof Keyport, N.J. and those manufactured by Boehringer Ingelheim ofIngelheim, Germany under the trade name HYDROCEROL®.

[0380] When blowing agents such as sodium bicarbonate and chemicalblowing agents are used in the example gel material, the materialtemperature is preferably adjusted just prior to addition of the blowingagent so that the material temperature is just above the blowingtemperature of the blowing agent. Following; addition of the blowingagent to the material, the material is allowed to cool so that it willretain the gas bubbles or gas pockets formed by the release of gas fromthe blowing agent. Preferably, the material is quickly cooled to atemperature below its Tg. The material will retain more gas bubbles andthe gas bubbles will be more consistently dispersed throughout thematerial the quicker the material temperature cools to a temperaturebelow the Tg.

[0381] When a example gel material is injection molded in accordancewith one example compounding; method of the gel material, foaming isexample just after the material has been injected into a mold. Thus, asthe material passes through the injection molding machine nozzle, itstemperature is preferably just higher than the blowing temperature ofthe blowing agent. Preferably, the material is then cooled to atemperature below its Tg.

[0382] Addition of poly isobutylene resin improves the ability of theexample gel material to foam and retain cells during; the foaming;process. One such resin, known as VISTANEX® LM MS, is manufactured byExxon Chemical Company. Similarly, surfactants, dispersants andemulsifiers such as Laureth-23, available from Lonza of Fair Lawn, N.J.under the trade name ETHOSPERSE LA-23, and others may be used tofacilitate foaming of the gel material. In formulations which includeoil, certain foaming oils such as Hydraulic and Transmission Oil, suchas that made by Spectrum Corp. of Selmer, Tenn., may also be used in thematerial to facilitate foaming of the materials.

[0383] Additives which modify the gas permeability of the example gelmaterial are example when the material is foamed. One such material,manufactured by Rohm & Haas Company of Philadelphia, Pa. and marketedunder the trade name PARALOID® K 400, modifies the gas permeability ofthe example gel material, facilitating the material's ability to holdgas bubbles.

[0384] When foaming is desired, additives which increase the meltviscosity or melt body of the material are also useful. One suchadditive, PARALOID® K 400, is believed to increase the melt viscosity ofthe material, making it more difficult for gas bubbles to escape fromthe material as it cools. Another additive, ACRYLOID® F-10, manufacturedby Rohm & Haas, is also believed to improve the ability of the materialto entrap bubbles.

[0385] Another additive, ethylene vinyl acetate (EVA) crosslinks withitself and/or other molecules to increase the internal structure of thematerial, while reducing the material's melt viscosity. Thus, EVA isalso believed to improve the gas bubble retention of the material. EVAis available from a variety of sources. High viscosity plasticizers,including without limitation DUOPRIME 500, are also believed tofacilitate gas bubble retention.

[0386] Additives which act as nucleating agents are also useful forfoaming the example gel material. Such additives are helpful ininitiating the formation of gas bubbles. Applicant believes thatantioxidants, including but not limited to IRGANOX® 1010 and IRGATOS®168, act as nucleating agents during foaming of the material. Blowingagents such as those sold under the trade name SAFOAM® by ReedyInternational are also believed to have a secondary function asnucleating agents. Examples of other nucleating agents include talc,carbon black, aluminum stearate, hydrated alumina, titanium dioxide,aluminum lake colorants, and others.

[0387] Referring now to FIGS. 40a and 40 b, a example embodiment of amethod for foaming the example gel cushioning material is shown. FIG.40a illustrates the example embodiment of the foaming method using anextruder 4001. FIG. 10b shows the example embodiment of the foamingmethod in an injection molding machine 4001′. Preferably, the gelcushioning medium includes a blowing agent such as SAFOAM® FP-40, whichis added to the non-liquid components of the cushioning medium prior toprocessing. About half of the plasticizer component is then added to thenon-liquid components, which are then fed into extruder 4001 orinjection molding machine 4001′. The remaining plasticizer is added tothe mixture at 4003, 4003′ as the mixture moves along the barrel 4004,4004′, which houses the screw or screws. Pressurized carbon dioxide(CO2), which is contained in a CO2 source 4008, 4008′ such as apressurized cannister, is then injected into the barrel. The CO2 isinjected into the mixture near the end of the barrel 4004, 4004′, aftera seal 4006, 4006′ and just before the nozzle 4007, 4007′. Preferably, apumping mechanism 4009, 4009′ such as a stepping pump, which are widelyused in the industry, is used to increase the pressure in barrel 4004,4004′. The material is then discharged through nozzle 4007, 4007′.

[0388] Referring to FIG. 40a, when an extruder 4001 is used to compoundand foam the example gel cushioning medium, a gear pump 4010, which ispreferably positioned at the end of nozzle 4007, controls the amount ofpressure in barrel 4004 and inhibits a drop in pressure at the nozzle.As the material is discharged from pump 4010 at 4011, the CO₂ expands,which introduces gas bubbles into the material and foams the material.

[0389] With reference to FIG. 40b, when an injection molding machine4001′ is used to compound and foam the example gel material, anaccumulator positioned just before nozzle 4007′ increases the materialpressure. Following discharge from nozzle 4007′, the material passesthrough a heat exchanger 4012 and into the cavity (not shown) of a mold4013. Preferably, the CO2 begins to expand and form gas bubbles in thematerial as the material fills the mold cavity.

[0390] Preferably, the CO2, and the material are maintained at apressure of at least about 700 psi just prior to entering the gear pumpat the extrusion end of the barrel. More preferably, the material andCO2 reach a pressure of at least about 900 psi. Most preferably, theCO2, and material are subjected to a pressure of at least about 1,700psi.

[0391] At pressures of about 1,700 psi and greater, CO2 acts as asupercritical fluid. At such high pressure, the liquid CO2 solvates theblock copolymer and principle polymer, which decreases the Tg of themixture. Thus, as pressure is released upon extrusion of the mixturefrom the nozzle, the CO2 immediately becomes a gas and the mixtureimmediately crosses its Tg. In other words, as gas bubbles are formingin the material, the material begins to solidify. Thus, the number ofgas bubbles retained in the material is increased. CO2 bubbles arebelieved to form around the SAFOAMO, which is believed to act as anucleating agent.

[0392] The expansion rate of the CO2 bubbles and the solidification rateof the mixture are varied, depending upon the particular formulation ofthe material. Various other factors also affect how a material willfoam, including the rate at which material is fed into the barrel (the“feed rate”), the length of time the material is in the barrel (the“residence time”), the speed at which the screw or screws rotate (the“screw rpm”), the relative direction each screw rotates and others.

[0393] In addition, properties of the material affect the foamingprocess. The amount of plasticizer affects a material's ability to foam.For example, when the plasticizer is an oil, materials which includeincreased amounts of plasticizer do not foam as readily as similarmaterials with less plasticizing oil. Applicant believes that as theamount of plasticizing oil in a material increases, gas bubbles tend tomore readily escape from the material.

[0394] d. Lattice Structures

[0395] Lattice structures may be made using the example gel material,which is incorporated into the cushion configurations. Such latticestructures include multiple overlaid streams of the gel material in alattice-like arrangement. Preferably, the streams of material have athickness of less than about one-tenth of an inch.

[0396] Formation of the gel material into lattice structures decreasesthe specific gravity of the material due to the free space createdwithin the lattice structure. Preferably, lattice structures reduce thespecific gravity of the material by at least about 50%.

[0397] One method of foaming lattice structures includes heating thematerial to a molten state and spraying streams of the material to forma desired lattice structure. Preferably, a hot melt adhesive spray gun,such as the FP-200 Gun System manufactured by Nordson Corporation ofAmherst, Ohio, is used to, spray streams of the example gel cushioningmaterial to form a lattice structure.

[0398] e. Premixing of Microspheres

[0399] In formulations of the example material for use in the cushioningelements hereof which include microspheres, premixing the microsphereswith the plasticizer prior to adding the plasticizer to the elastomericblock copolymer and the polyolefin may result in a more uniform mixture(i.e., a better final product) and makes the microsphere-containing gelmaterial easier to process. For example, the materials may be premixedby hand.

[0400] f. Pre-Manufacture of Pellets

[0401] In some embodiments, it will be example to prepare pelletizedgelatinous elastomer material for later use in manufacturing cushioningdevices or other devices. The pelletized gelatinous elastomer could beof any formulation described herein or otherwise, and could contain anydesired additives. The pellets could be produced by first compoundingthe material and forming it into pellets for later use in an appropriatemanufacturing process.

[0402] 5. Representative Elastomeric Gel Physical Properties andFormulations

[0403] When the example A-B-A triblock copolymer, plasticizer andadditives are mixed, the resultant material is very strong, yet veryelastic and easily stretched, having a Young's elasticity modulus ofonly up to about 1×106 dyne/cm2. The example elastomeric gel materialfor use in the cushioning elements hereof also has low tack and littleor no oil bleed, both of which are believed to be related to themolecular weight of the uniquely example elastomers as well as themolecular structure of the elastomer and its interaction with theplasticizing component. Finally, the example elastomeric gel cushioningmedium is capable of elongation up to about 2400% and more.

EXAMPLES

[0404] Examples 1 through 14 include various mixtures of SEPTON 4055(available from Kuraray) ultra high molecular weightpolystyrene-hydrogenated poly(isoprene+butadiene) polystyrene triblockcopolymer extended in a plasticizing oil. In addition, the materials ofExamples 1 through 14 include very minor amounts of IRGANOX® 1010 (about0.03%), IRGAFOSV 168 (about 0.03%), and colorant (about 0.04%).

[0405] The material of each of Examples I through 14 was compounded inan ISF 120 VL injection molding machine, manufactured by Toshiba MachineCo. of Tokyo, Japan, with a 20:1 (UD) high mixing single screwmanufactured by Atlantic Feed Screw, Inc. of Cayce, S.C. The temperaturein the injection molding machine was increased stepwise from the pointof insertion to the injection nozzle. At the point of insertion, thetemperature was about 270° F. Temperatures along the screw were about275° F. and about 280° F., with the temperature increasing as thematerial approached the injection nozzle. The temperature at theinjection nozzle was about 290° F. This gradual increase in temperaturebuilds up pressure during feeding of the material through the injectionmolding machine, providing a more homogeneous mixture of the componentsof the material.

[0406] Each of the formulations of Examples 1 through 11 were theninjected into an aluminum plaque mold and allowed to cure at roomtemperature for about 24 hours to about 48 hours. Thereafter, varioustests were performed on the materials, including percent elongation,tensile strength at break, and percent oil bleed.

[0407] Percent elongation and tensile strength testing were performed inaccordance with American Society for Testing and Materials (ASTM)Standard Test Method D412, using a Model QC-11-30XS-B Electronic TensileTester manufactured by Thwing Albert Instrument Co. of Philadelphia, Pa.Each of samples were O-shaped rings with an outer diameter of about0.500 inch, an inner diameter of about 0.375 inch, a gauge diameter ofabout 0.438 inch, and a mean circumference of about 1.374 inches. Fivesamples of each material were tested for elongation and tensilestrength.

[0408] Percent oil bleed was measured by obtaining the combined weightof three disk-shaped samples of the material, each sample havingdiameter of about 3 cm and a thickness of about 6.5 nun. Two pieces of12.5 cm diameter qualitative filter paper having a medium filter speedand an ash content of about 0.15%, such as that sold under the tradename DOUBLE RINGS 102, and manufactured by Xinhua Paper Mill, were thenweighed individually.

[0409] The three sample disks were then placed on one of the pieces offilter paper (which has high capillary action), and the other piece offilter paper was placed on top of the samples. The material and paperwere then placed in a plastic bag and pressure-sandwiched between twoflat steel plates, each weighing within about 0.5% of about 2285 g.Next, the material samples, paper and steel plates were placed in afreezer at about −4° C. for about 4 hours.

[0410] Oil bleed testing was conducted at a low temperature becauserubber molecules are known to constrict at low temperatures. Thus, intheory, when a plasticized material is subjected 95 to coolertemperatures, the attraction of plasticizer to Vander Waals bindingsites on the rubber molecules decreases. Therefore, it has beentheorized that plasticizer-extended materials tend to bleed more atlower temperatures. However, oil tends to flow more slowly at lowtemperatures, suggesting that this theory may not be accurate.Nevertheless, this theory has been widely accepted. The extremecondition of the pressure and the freezer was needed for quantitativeevaluation since the example elastomeric gel materials have theadvantage over prior art gel materials of not bleeding at all at roomtemperature without pressure, even when placed next to high capillaryaction paper. Although John Y. Chen did not report oil bleed in hispatents or patent applications, Applicant's experience is that Chen'smaterials have a higher level of oil bleed than the example elastomericgel cushioning medium.

[0411] Upon removal from the freezer, each piece of the filter paper andthe samples were immediately weighed again. Percent oil bleed was thencalculated by determining the combined weight increase of the filterpapers, dividing that value by the original sample weight andmultiplying the result by 100.

Example 1

[0412] The material of Example 1 includes eight parts LP 150 mineral oilto one part SEPTON 4055. 8:1 Average High Value Percent Elongation 23752400 PSI at Failure 185 190

[0413] In comparison, the! material of Chen's patents that has an oil toelastomer ratio of 4:1, which should have higher strength thanApplicant's 8:1 material of Example 1, instead exhibits much lowerelongation and PSI at failure (i.e., tensile strength) values. Thematerial of Example 1 elongates up to about 2,400%, which is 700%greater elongation than Chen's 4:1, which is capable of only 1700%elongation (See, e.g., '213 patent, Table 1, col. 6, lines 18-38).Likewise, the tensile strength at break of Chen's 4:1 gel is only about4×10⁶ dyne/cm', or 58 psi. Thus, the 8:1 material of Example 1 is atleast three times as strong as Chen's 4:1. This is an unexpectedly goodresult since the conventional wisdom concerning gels is that more oilresults in less strength. Applicant doubled the amount of oil used (8:1compared to 4:1) but achieved more than three times the tensile strengthof Chen's material.

Example 2

[0414] The material of Example 2 includes five parts LP 150 mineral oilto one part SEPTON 4055. 5:1 Average High Value Percent Elongation 19752030 PSI at Failure 335 352

[0415] A comparison of the 5:1 material of Example 2 to the 4:1 materialof Chen's patents shows that Chen's material exhibits much lowerelongation and PSI at failure (i.e., tensile strength) values. Thematerial of Example 2 elongates up to about 2,000%, which is about 300%more than Chen's 4:1, which is capable of only 1700% elongation (See,e.g., '213 patent, Table I, col. 6, lines 18-38). Likewise, the tensilestrength at break of Chen's 4:1 gel is only about 4×106 dyne/cm2, whichtranslates to only about 58 psi. Thus, the 5:1 material of Example 2,despite the presence of about 25% more oil than Chen's 4:1 material, isabout five-and-a-half times as strong as Chen's 4:1.

Example 3

[0416] The material of Example 3 includes three parts LP 150 mineral oilto one part SEPTON 4055. 3:1 Average High Value Percent Elongation 15551620 PSI at Failure 404 492

[0417] A consideration of both Example 2, a material having a 5:1 oil toelastomer ratio, and Example 3, a material having a 3:1 oil to elastomerratio, indicates that a material with a 4:1 oil to elastomer ratio wouldcompare very favorably to the gel disclosed in U.S. Pat. No. 5,508,334,which issued in the name of John Y. Chen. According to Table I in the'334 patent, Chen's 4:1 KRATON® G-1651-containing material had abreaking strength (i.e., tensile strength) value of 4×106 dyne/cm2,which translates to only about 58 psi.

[0418] The elongation at break value was mysteriously omitted from TableI of the '334 patent and other Chen patents. However, reference to TableI of Chen's first two issued patents (the '284 and '213 patents) setsthe percent elongation of Chen's 4:1 material at about 1700. Applicantsuspects that Chen omitted this data in later patent applicationsbecause it was either inaccurate or Chen's improved materials failed toexhibit improved properties over his earlier materials.

[0419] In comparison, the percent elongation of a 4:1 exampleelastomeric gel material for use in the cushions would be at least about1800, exceeding the elongation of Chen's 4:1 material by about 100% ormore. Similarly, the tensile strength of a 4:1 material example for usein the cushions hereof would be at least about 350 psi, and probably inthe 370 to 375 psi range. Thus, a example elastomenc gel cushioningmedium for use in the cushions with an oil to elastomer ratio of about4:1 would be about six times a strong as Chen's most example 4:1 gel.

[0420] The following Examples 4 through 11 have been included todemonstrate the usefulness of various plasticizing oils in the exampleelastomeric gel material.

Example 4

[0421] The material of Example 4 included eight parts of a plasticizermixture to one part SEPTON 4055. The eight parts plasticizer mixtureincluded about 5.3 parts REGALREZ© 1018 and about 2.8 parts DUOPRIME(g)90 mineral oil. 8:1 Average High Value Percent Elongation 2480 2520 PSIat Failure 187 195

Example 5

[0422] The material of Example 5 included eight parts of EDELEX® 27 oilto one part SEPTON 4055. EDELEX© 27 has an aromatic content of about 1%,which would be expected to slightly decrease the tensile strength of thematerial. 8:1 Average High Value Percent Elongation 2105 2150 PSI atFailure 144 154 Percent oil bleed 0.34

Example 6

[0423] The material of Example 6 included eight parts of DUOPRIMEO 55mineral oil to one part SEPTON 4055. 8:1 Average High Value PercentElongation 1940 2055 PSI at Failure 280 298 Percent oil bleed 0.29

Example 7

[0424] The material of Example 7 included eight parts of DUOPRIME® 70mineral oil to one part SEPTON 4055. 8:1 Average High Value PercentElongation 2000 2030 PSI at Failure 250 275 Percent oil bleed 0.41

Example 8

[0425] The material of Example 8 included eight parts of DUOPRIME® 90mineral oil to one part SEPTON 4055. 8:1 Average High Value PercentElongation 2090 2125 PSI at Failure 306 311 Percent oil bleed 0.35

Example 9

[0426] The material of Example 9 included eight parts of DUOPRIME® 200mineral oil to one part SEPTON 4055. 8:1 Average High Value PercentElongation 1970 2040 PSI at Failure 200 228 Percent oil bleed 0.20

Example 10

[0427] The material of Example 10 included eight parts of DUOPRIME® 350mineral oil to one part SEPTON 4055. 8:1 Average High Value PercentElongation 2065 2080 PSI at Failure 267 270 Percent oil bleed 0.21

Example 11

[0428] The material of Example 11 included eight parts of DUOPRIME® 500mineral oil to one part SEPTON 4055. 8:1 Average High Value PercentElongation 1995 2075 PSI at Failure 194 223 Percent oil bleed 0.17

Example 12

[0429] Component Generic Class Amount (grams) Septon 4055 A-B-Acopolymer 227.0 Duoprime 500 oil Plasticizing oil 2,722.0 Irganox 1010Antioxidant 4.5 Irgafos 168 Antioxidant 4.5 Safoam FP-40 Foaming agent14.0 Lamp Black Colorant and Foam Bubble 1.5 Nucleating Agent

[0430] Applicant began foaming the example elastomeric gel material toreduce its specific gravity by heating it until the SAFOAM began todegenerate and create CO2 gas. DUOPRIME 500 oil was selected for use inthe example because of its high viscosity (i.e., it would help hold abubble longer than a lower viscosity oil). The components werecompounded in an injection molding machine according to one example meltblending method. The original mixture included 3.40 g SAFOAM. When halfof the SAFOAM appeared to have been consumed, 3.40 g more was added.Another 7.20 g of SAFOAM was added when half of the SAFOAM againappeared to have been consumed. Temperatures along the injection moldingscrew ranged from about 280° F. at the point of insertion to about 240°F. at the nozzle. The material of Example 12 had closed cells of fairlyconsistent density.

Example 13

[0431] Component Generic Class Amount (grams) Septon 4055 A-B-Acopolymer 227.0 Duoprime 500 oil Plasticizing oil 2,722.0 Irganox 1010Antioxidant 1.5 Irgafox 168 Antioxidant 1.5 Expancell DE-80 Microspheres500.0 Orange Colorant 2.0

[0432] Applicant has also used microspheres to reduce the specificgravity of the example elastomeric gel cushioning medium. Acrylicmicrospheres were used in the material of Example 13. The componentswere premixed, then compounded in an injection molding machine screw.Temperatures along the injection molding screw ranged from about 260° F.at the point of insertion to about 220° F. at the nozzle. Surprisingly,the microspheres were not deformed by the high shear and hightemperatures of the injection molding machine. The resulting materialwas very light, with microspheres consistently dispersed therethrough.

Example 14

[0433] Component Generic Class Amount (grams) Septon 4055 A-B-Acopolymer 114.0 Kraton G-1701 A-B copolymer 5.8 Regalrez 1018Plasticizing resin 340.0 Edelex 45 Plasticizing oil 225.0 Talc Talc 20.4Vestenamer 8012. Tor rubber 11.5 Expancell DU-80 Microspheres 0.5 SafoamFP-40 Foaming agent 10.0 Irganox 1010 Antioxidant 3.0 Irgafos 168Antioxidant 3.0 Boiled Linseed Oil 8.0 Green Colorant 2.0

[0434] In the material of Example 14, Applicant used KRATON® G-1701,manufactured by Shell Chemical Co., to reduce oil bleed. R:EGALREZ® 1018was used as a plasticizer and to reduce oil bleed from the material.Talc was included in the material of Example 14 to act as a nucleatingagent during foaming of the material. Since talc migrates to the surfaceof the material, it is also useful as a surface detackifier. Talc mayalso be used as a filler in the material. VESTENAMER 8012, sold by MilsAmerica Inc. of Piscataway, N.J., is a transpolyoctylene rubber (tor)which is useful for reducing oil bleed and reducing melt viscosity ofthe example elastomeric gel material. Boiled linseed oil is believed toreduce the melt viscosity and tackiness of the material and toaccelerate the migration of particulate matter to the material'ssurface. Applicant used both microspheres and foaming agents in thematerial of Example 14. Although acrylic microspheres reduce thespecific gravity of the example elastomeric gel material, they increasethe stiffness of the material, though not as much as glass, ceramic, orother rigid microspheres would.

[0435] The closed cell foaming and the microsphere dispersion of thematerial of Example 14 were consistent. The material was soft andlight-weight. The components were well compounded. In addition, thematerial of Example 14 did not have an oily feel and exhibited noplasticizer bleedout at room temperature.

[0436] Additives such as colorants, flame retardants, detackifiers andother additives may be included in the example elastomeric gelcushioning medium. Various formulations of the example elastomeric gelmaterial may be tailored to achieve differing levels of softness,strength, tackiness and specific gravity as desired. Examples 1 through11 illustrate the surprisingly high elongation and tensile strength ofthe material. Many embodiments of the example elastomeric material, ofwhich the preceding examples are representative, exhibit physicalproperties vastly superior to those of John Y. Chen's material, whichApplicant believes to be the closest and best prior art. A chemicalexplanation for the superior results is provided below.

[0437] Examples 15 through 35 are other formulations of the exampleelastomeric gel cushioning medium for use in the cushions. Theformulations of Examples 15 through 35 were compounded using a ZE25TIEBAR AIR COOLED TWIN SCREW EXTRUDER with a 35:1 L/D ratio according toa example melt blending method. Temperatures along the screws were inthe range of about 130° C. to about 170° C. at the hopper to about 100°C. to about 130° C. at the nozzle.

Example 15

[0438] Component Generic Class Amount (grams) Septon 4055 A-B-Acopolymer 50.04 LP-150 Plasticizing oil 250.0 Irganox 1010 Antioxidant1.5 Irgafos 168 Antioxidant 1.5

Example 16

[0439] Component Generic Class Amount (grams) Septon 4055 A-B-Acopolymer 83.25 LP-150 Plasticizing oil 250.00 Irganox 1010 Antioxidant1.5 Irgafos 168 Antioxidant 1.5

Example 17

[0440] Component Generic Class Amount (grams) Septon 4055 A-B-Acopolymer 50.04 Kadol Plasticizing oil 250.00 E17 Antioxidant (vitaminE) 6.26

Example 18

[0441] Component Generic Class Amount (grams) Septon 4055 A-B-Acopolymer 250.00 Duoprime 90 Plasticizing oil 1,250.00 E17 Antioxidant(vitamin E) 6.30

Example 19

[0442] Component Generic Class Amount (grams) Septon 4055 A-B-Acopolymer 250.00 LP-150 A-B-A copolymer 1,250.00 E17 Antioxidant(vitamin E) 6.25

Exhibit 20

[0443] Component Generic Class Amount (grams) Septon 4055 A-B-Acopolymer 350.00 Regalrez 1018 Plasticizing resin 262.51 C23 to C27Alkane Wax Plasticizer 35.00 LP-150 Plasticizing oil 287.60 E 17Antioxidant (vitamin E) 14.00 Ethosperse 52.50 White Colorant 10.50Yellow Colorant 0.70 Red Colorant 0.03

Example 21

[0444] Weight % Component Generic Class of Total SEPTON ® 4055 Triblockcopolymer 11.89 KRATON ® G 1701 Diblock copolymer 0.24 LP-150 mineraloil Plasticizer 73.87 Astor Slack Wax 2050 Plasticizer 8.33 Alkane Wax C25-27 Plasticizer 0.59 IRGANOX ® 1010 Antioxidant 0.42 IRGAFOS ® 168Antioxidant 0.42 IRGANOX ® E17 Antioxidant 0.42 TETRAGLYME Anti-bleed,anti-tack additive 1.19 PQ 6546 Acrylic Microspheres 1.44 Rocket RedColorant 1.19

Example 22

[0445] Weight % Component Generic Class of Total SEPTON ® 4055 Triblockcopolymer 14.86 KRATON9 G 1701 Diblock copolymer 0.30 LP-150 mineral oilPlasticizer 71.01 Astor Slack Wax 2050 Plasticizer 6.69 Alkane Wax C25-27 Plasticizer 0.58 IRGANOX ® 1010 Antioxidant 0.52 IRGAFOS ® 168Antioxidant 0.52 IRGANOX ® E17 Antioxidant 0.52 TETRAGLYME Anti-bleed,anti-tack additive 1.34 PQ 6546 Acrylic Microspheres 1.44 Rocket RedColorant 2.23

Example 23

[0446] Weight % Component Generic Class of Total SEPTON ® 4055 Triblockcopolymer 16.66 KRATON ® G 1701 Diblock copolymer 0.33 LP-150 mineraloil Plasticizer 67.48 Astor Slack Wax 2050 Plasticizer 7.50 Alkane Wax C25-27 Plasticizer 0.67 IRGANOX ® 1010 Antioxidant 0.58 IRGAFOS ® 168Antioxidant 0.58 IRGANOX ® E17 Antioxidant 0.58 TETRAGLYME Anti-bleed,anti-tack additive 1.50 PQ 6546 Acrylic Microspheres 1.62 Rocket RedColorant 2.50

Example 24

[0447] Weight % Component Generic Class of Total SEPTON ® 4055 Triblockcopolymer 13.18 KRATON ® G 1701 Diblock copolymer 0.26 LP-150 mineraloil Plasticizer 75.12 Astor Slack Wax 2050 Plasticizer 5.27 Alkane Wax C25-27 Plasticizer 0.33 IRGANOX ® 1010 Antioxidant 0.46 IRGAFOS ® 168Antioxidant 0.46 IRGANOX ® E 17 Antioxidant 0.46 TETRAGLYME Anti-bleed,anti-tack additive 1.19 PQ 6546 Acrylic Microspheres 1.62 Horizon BlueColorant 1.65

Example 25

[0448] Weight % Component Generic Class of Total SEPTON ® 4055 Triblockcopolymer 11.07 KRATON ® G 1701 Diblock copolymer 0.22 LP-150 mineraloil Plasticizer 76.89 Astor Slack Wax 2050 Plasticizer 5.54 Alkane Wax C25-27 Plasticizer 0.55 IRGANOX ® 1010 Antioxidant 0.39 IRGAFOS ® 168Antioxidant 0.39 IRGANOX ® E 17 Antioxidant 0.39 Amyl Formate Clarityenhancer 0.55 (supplied by Aldrich) TETRAGLYME Anti-bleed, anti-tackadditive 1.66 PQ 6546 Acrylic Microspheres 0.97 Horizon Blue Colorant1.38

Example 26

[0449] Weight % Component Generic Class of Total SEPTON ® 4055 Triblockcopolymer 14.40 KRATON ® G 1701 Diblock copolymer 0.29 LP-150 mineraloil Plasticizer 74.50 Astor Slack Wax 2050 Plasticizer 4.80 Alkane Wax C25-27 Plasticizer 0.50 IRGANOX ® 1010 Antioxidant 0.50 IRGAFOS ® 168Antioxidant 0.50 IRGANOX ® E17 Antioxidant 0.50 TETRAGLYME Anti-bleed,anti-tack additive 1.44 PQ 6546 Acrylic Microspheres 0.97 Signal GreenColorant 1.58

Example 27

[0450] Weight % Component Generic Class of Total SEPTON ® 4055 Triblockcopolymer 13.37 KRATON ® G 1701 Diblock copolymer 0.27 LP-150 mineraloil Plasticizer 74.88 Astor Slack Wax 2050 Plasticizer 5.35 Alkane Wax C25-27 Plasticizer 3.34 IRGANOX ® 1010 Antioxidant 0.47 IRGAFOS ® 168Antioxidant 0.47 IRGANOX ® E17 Antioxidant 0.47 TETRAGLYME Anti-bleed,anti-tack additive 1.34 Amyl Formate Clarity Enhancer 0.40 PQ 6546Acrylic Microspheres 0.99 Signal Green Colorant 1.47

Example 28

[0451] Weight % Component Generic Class of Total SEPTON ® 4055 Triblockcopolymer 8.14 KRATON ® G 1701 Diblock copolymer 0.16 LP-150 mineral oilPlasticizer 80.76 Astor Slack Wax 2050 Plasticizer 6.51 Alkane Wax C25-27 Plasticizer 0.49 IRGANOX ® 1010 Antioxidant 0.28 IRGAFOS ®168Antioxidant 0.28 IRGANOX ® E17 Antioxidant 0.28 TETRAGLYME Anti-bleed,anti-tack additive 1.22 PQ 6546 Acrylic Microspheres 0.97 Blaze OrangeColorant 0.90

Example 29

[0452] Weight % Component Generic Class of Total SEPTON ® 4055 Triblockcopolymer 8.12 KPATON ® G 1701 Diblock copolymer 0.16 LP-150 mineral oilPlasticizer 80.60 Astor Slack Wax 2050 Plasticizer 6.50 Alkane Wax C25-27 Plasticizer 0.49 IRGANOX ® 1010 Antioxidant 0.28 IRGAFOS ® 168Antioxidant 0.28 IRGANOX ® E 17 Antioxidant 0.28 TETRAGLYME Anti-bleed,anti-tack additive 1.22 Amyl Formate Clarity Enhancer 0.20 PQ 6546Acrylic Microspheres 0.97 Blaze Orange Colorant 0.90

Example 30

[0453] Weight % Component Generic Class of Total SEPTON ® 4055 Triblockcopolymer 12.10 KRATON ® G 1701 Diblock copolymer 0.30 LP-150 mineraloil Plasticizer 84.47 IRGANOXID 1010 Antioxidant 0.18 IRGAFOS ® 168Antioxidant 0.18 FC-10 fluorochemical alcohol Bleed-reducing additive0.18 Strong Magenta Colorant 0.36 Horizon Blue Colorant 0.36 PQ 6545Acrylic Microspheres 1.62

Example 31

[0454] Weight % Component Generic Class of Total SEPTON ® 4055 Triblockcopolymer 19.69 LP-150 mineral oil Plasticizer 78.78 IRGANOXt 1010Antioxidant 0.20 IRGAFOS ® 168 Antioxidant 0.20 DYNTAMAR ® FX 9613Bleed-reducing additive 0.15 091DU80 Acrylic Microspheres 0.98

Example 32

[0455] Weight % Component Generic Class of Total SEPTON ® 4055 Triblockcopolymer 19.60 LP-150 mineral oil Plasticizer 78.39 IRGANOX ® 1010Antioxidant 0.19 IRGAFOS ® 168 Antioxidant 0.20 DYNAMAR ® FX 9613Bleed-reducing additive 0.15 091 DU80 Acrylic Microspheres 1.47

Example 33

[0456] Weight % Component Generic Class of Total SEPTON ® 4055 Triblockcopolymer 28.38 LP-150 mineral oil Plasticizer 70.92 IRGANOX ® 1010Antioxidant 0.28 IRGAFOS ® 168 Antioxidant 0.28 ZONYL ® BA-NBleed-reducing additive 0.14

Example 34

[0457] Weight % Component Generic Class of Total SEPTON ® 4055 Triblockcopolymer 23.43 LP-150 mineral oil Plasticizer 58.55 IRGANOX ® 1010Antioxidant 0.23 IRGAFOS ® 168 Antioxidant 0.23 Carbowax Plasticizer,includes 17.56 polar molecules

Example 35

[0458] Weight % Component Generic Class of Total SEPTON ® 4055 Triblockcopolymer 15.14 SEPTON ® 4033 Triblock copolymer 3.79 LP-150 mineral oilPlasticizer 80.45 IRGANOX ® 1010 Antioxidant 0.19 IRGAFOS ® 168Antioxidant 0.19 ZONYL ® BA-N Bleed-reducing additive 0.15 Horizon BlueColorant 0.09

[0459] 6. Representative Visco-Elastomeric Gel Formulations

[0460] The following examples have been prepared by Applicant.

Example 36

[0461] Weight % Component Generic Class of Total Septon 4055 A-B-Acopolymer 5.46 Kraton G1701 A-B copolymer 0.55 Irganox 1010 antioxidant0.16 Ireafos 168 antioxidant 0.16 LP-150 plasticizing oil 32.77 Regalrez1018 plasticizing resin 54.62 Kristalex 5140 strengthening resin 0.55Regalite R101 plasticizing resin 2.73 Regalrez 1139 plasticizing resin2.73 PQ 6545 added to increase rebound rate 0.16 microspheres anddecrease specific gravity Bright orange colorant 0.11 aluminum lake

[0462] SEPTON® 4055 imparts form and strength to the visco-elasticmaterial. KRATON® G-1701 is used to facilitate a more homogeneous blendof the elastomer (A-B-A copolymer) and plasticizer components. REGALREZ®1018, a room temperature liquid plasticizer, is the primary plasticizerused in the material. REGALITE® R101 and REGALREZ® 1139 are alsoplasticizers and modify the tack of the visco-elastic material.KRISTALEX® 5140 is believed to impart strength to the styrene domains orcenters of the A-B-A copolymer. It is also believed to have someplasticizing abilities when used in combination with A-B-A copolymers.IRGANOX® 1010 and IRGAFOS® 168 are antioxidants. The material of Example36 was made as an early experiment. Consequently, LP-150, a plasticizingoil, was used in combination with the resin plasticizers.

[0463] The material of Example 36 was prepared by premixing thecomponents and melt blending them in an injection molding machineaccording to one example method for compounding the example gelcushioning medium. The material was very tacky and readily deformable,had very quick rebound and was very soft. Applicant believes that thevery quick rebound rate is caused by the presence of plasticizing oiland microspheres. The specific gravity of the material was about 0.40.

Example 37

[0464] Weight % Component Generic Class of Total Septon 8006 A-B-Acopolymer 2.42 Septon 4055 A-B-A copolymer 2.42 Kraton G1701 A-Bcopolymer 0.48 Irganox 1010 antioxidant 0.15 Irgafos 168 antioxidant0.15 Regalrez 1018 plasticizing resin 87.18 Kxistalex 5140 strengtheningresin 0.48 Regalite R101 plasticizing resin 2.42 Regalrez 1139plasticizing resin 2.42 PQ 6545 added to increase rebound rate 1.39microspheres and decrease specific gravity Bright orange colorant 0.24aluminum lake Dow Corning rubber additive 0.24 200 silicone

[0465] In the material of Example 37, SEPTON® 8006 was used incombination with SEPTON® 4055 to provide some form, but a softervisco-elastic material. Silicone was added to detackify the material.The material of 5xample 37 was prepared by premixing the components andmelt blending them in an injection molding machine according to aexample method for compounding the example gel material. The materialwas slightly tacky and readily deformable, had slow rebound and moderatestiffness. The use of silicone seems to have decreased the tackiness ofthe material. The specific gravity of the material was about 0.30.

Example 38

[0466] Weight % Component Generic Class of Total Septon 8006 A-B-Acopolymer 2.45 Septon 4055 A-B-A copolymer 2.45 Kraton G1701 A-Bcopolymer 0.49 Iroanox 1010 antioxidant 0.15 Irgafos 168 antioxidant0.15 Regalrez 1018 plasticizing resin 88.38 Kristalex 5140 strengtheningresin 0.49 Regalite R101 plasticizing resin 2.46 Regalrez 1139plasticizing resin 2.46 PQ 6545 added to increase rebound rate 0.28microspheres and decrease specific gravity Bright orange colorant 0.25aluminum lake

[0467] The material of Example 38 was prepared by premixing thecomponents and melt blending them in an injection molding machineaccording to a example method for compounding the example gel materialfor use in the cushions. The material was very tacky and readilydeformable, had a slow to moderate rebound rate and was extremely soft.The specific gravity of the material was about 0.65. 13

Example 39

[0468] Weight % Component Generic Class of Total Septon 8006 A-B-Acopolymer 2.45 Septon 4055 A-B-A copolymer 2.45 Kraton G 1701 A-Bcopolymer 0.49 Irganox 1010 antioxidant 0.15 Irgafos 168 antioxidant0.15 Regalrez 1018 plasticizing resin 88.06 Kristalex 5140 strengtheningresin 0.49 Regalite R101 plasticizing resin 2.45 Regalrez 1139plasticizing resin 2.45 PQ 6545 added to increase rebound rate 0.64microspheres and decrease specific gravity Bright orange colorant 0.24aluminum lake

[0469] The material of Example 39 was prepared by premixing thecomponents and melt blending them in an injection molding machineaccording to a example compounding method. The material was very tackyand readily deformable, had moderate rebound and moderate softness. Thespecific gravity of the material was about 0.44.

Example 40

[0470] Weight % Component Generic Class of Total Septon 8006 A-B-Acopolymer 2.43 Septon 4055 A-B-A copolymer 2.43 Kraton G 1701 A.-Bcopolymer 0.49 Irganox 1010 antioxidant 0.15 Irgafos 168 antioxidant0.15 Regalrez 1018 plasticizing resin 87.51 Kristalex 5140 strengtheningresin 0.49 Regalite R101 plasticizing resin 2.43 Regalrez 1139plasticizing resin 2.43 PQ 6545 added to increase rebound rate 1.26microspheres and decrease specific gravity Bright orange colorant 0.24aluminum lake

[0471] The material of Example 40 was prepared by premixing thecomponents and melt blending them in an injection molding machineaccording to a example compounding method. The material was tacky andreadily deformable, had very quick rebound and moderate softness. Thespecific gravity of the material was about 0.28.

Example 41

[0472] Weight % Component Generic Class of Total Septon 8006 A-B-Acopolymer 2.44 Septon 4055 A-B-A copolymer 2.44 Kraton G1701 A-Bcopolymer 0.49 Irganox 1010 antioxidant 0.15 Irgafos 168 antioxidant0.15 Regalrez 1018 plasticizing resin 87.78 Kristalex 5140 strengtheningresin 0.49 Regalite R101 plasticizing resin 2.44 Regalrez 1139plasticizing resin 2.44 PQ 6545 microspheres added to increase reboundrate 0.95 and decrease specific gravity Colorant-bright orange 0.24aluminum lake

[0473] The material of Example 41 was prepared by premixing thecomponents and melt blending them in an injection molding machineaccording to a example compounding method. The material was very tackyand readily deformable, had slow rebound and little stiffness. Thespecific gravity of the material was about 0.37.

Example 42

[0474] Weight % Component Generic Class of Total Septon 4033 A-B-Acopolymer 0.29 Septon 8006 A-B-A copolymer 4.05 Kraton G1701 A-Bcopolymer 0.09 Irganox 1010 antioxidant 0.12 Irgafos 168 antioxidant0.12 Regalrez 1018 plasticizing resin 86.73 Kristalex 5140 plasticizingresin 0.87 Regalite R101 plasticizing resin 2.02 Regalrez 1139plasticizing resin 2.02 Vistanex LM-MS plasticizing resin 2.89 PQ 6545microspheres added to increase rebound rate 0.37 and decrease specificgravity Safoam FP-powder blowing agent 0.43

[0475] In the material of Example 42, SEPTON® 4033 was used as a lowermolecular weight polymer to help trap foam bubbles. A greater weightpercentage of SEPTON® 8006 was used to 114 provide a visco-elastomericmaterial which was softer than the materials of the preceding examples.VISTANEX® LM-MS was also added to determine whether its presenceimproved the material's ability to retain foam bubbles.

[0476] In preparing the material of Example 42, the solid resins werefirst crushed and premixed. The VISTANEX® LM-MS was heated for thirtyminutes in an oven at about 150 to 200° C. The REGALREZ® and VISTANEX®were then mixed together with heat until the VISTANEX® appeared to becompletely solvated.

[0477] The components of the material of Example 42 were then meltblended in an injection molding machine according to a examplecompounding method. The material was very tacky and readily deformable,had very slow rebound and was very soft. The use of VISTANEX® LM-MSappears to have decreased the rebound rate of the material. The specificgravity of the material was about 0.61.

Example 43

[0478] Weight % Component Generic Class of Total Septon 4033 A-B-Acopolymer 0.29 Septon 8006 A-B-A copolymer 4.05 Kraton G1701 A-Bcopolymer 0.09 Irganox 1010 antioxidant 0.12 Irgafox 168 antioxidant0.12 Vistanex LM-MS Plasticizing resin 2.90 Regalrez 1018 Plasticizingresin 86.85 Kristalex 5140 Strengthening resin 0.87 Regalite R101Plasticizing resin 2.03 Regalrez 1139 Plasticizing resin 2.03 PQ 6545microspheres Added to increase rebound rate 0.67 and decrease specificgravity

[0479] In preparing the material of Example 43, the crystallized (notreadily flowable at room temperature) resins were first crushed andpremixed. The VISTANEX© LM-MS was heated for thirty minutes in oven atabout 150 to 200° C. The REGALREZ® and VISTANEX® were then mixedtogether with heat until the VISTANEX® appeared to be completelysolvated. The components of the material of Example 43 were then meltblended in an injection molding machine according to a example methodfor compounding the example gel cushioning media. The material was verytacky and readily deformable, had extremely slow, incomplete rebound andwas very soft. The specific gravity of the material was about 0.47.

Example 44

[0480] Weight % Component Generic Class of Total Septon 4077 A-B-Acopolymer 4.67 Irganox 1010 antioxidant 0.30 Irgafos 168 antioxidant0.30 Regalrez 1018 plasticizing resin 83.25 Vistanex LM-MS plasticizingresin 1.81 Kristale 5140 plasticizing resin 0.96 Regalite R101plasticizing resin 1.93 Regalrez 1139 plasticizing resin 1.93 PQ 6545microspheres added to increase rebound rate 0.60 and decrease specificgravity Glycerin detackifying agent 4.25

[0481] SEPTON® 4077 was included in the material of Example 44 toprovide form and strength to the material, yet provide a softer materialthan that using SEPTONO 4055. The crystallized (not readily flowable atroom temperature) resins of Example 44 were first crushed and premixed.The VISTANEX® LM-MS was heated for thirty minutes in oven at about 150to 200° C. The REGALREZ® and VISTANEX® were then mixed together withheat until the VISTANEXV appeared to be completely solvated.

[0482] The remaining components were then quickly mixed and melt blendedin an injection molding machine according to a example compoundingmethod. The material was very tacky (but less than a comparable materialwithout the glycerin), readily deformable, had extremely slow,incomplete rebound and moderate softness. Use of SEPTON® 4077 appears tohave resulted in a material which is softer than those which includeSEPTON® 4055 as the only plasticizer, but stiffer than materials of theprevious examples which have a combination of copolymers. The specificgravity of the material was about 0.40.

Example 45

[0483] Weight % Component Generic Class of Total Septon 1077 A-B-Acopolymer 4.67 Irganox 1010 antioxidant 0.30 Irgafos 168 antioxidant0.30 Regalrez 1018 plasticizing resin 83.25 Vistane LM-MS plasticizingresin 1.81 Kristalex 5140 strengthening resin 0.96 Regalite R101plasticizing resin 1.93 Regalrez 1139 plasticizing resin 1.93 PQ 6545microspheres added to increase rebound rate 0.60 and decrease specificgravity Glycerin detackifying agent 4.25

[0484] Glycerine was added to detackify the material of Example 45. Inpreparing the material of Example 45, the crystallized (not readilyflowable at room temperature) resins were first crushed and premixed.The VISTANEX® LM-MS was heated for thirty minutes in oven at about 150to 200° C. The REGALREZ® and VISTANEX® were then mixed together withheat until the VISTANEX® appeared to be completely solvated.

[0485] The remaining components were then mixed thoroughly and meltblended in an injection molding machine according to a examplecompounding method. The material was moderately tacky and readilydeformable, had quick rebound and was soft. Glycerine appears to havereduced the tackiness of the material. The specific gravity of thematerial was about 0.42.

Example 46

[0486] Weight % Component Generic Class of Total Septon 4055 A-B-Acopolymer 2.47 Septon 8006 A-B-A copolymer 2.47 Kraton G 1701 A-Bcopolymer 0.49 Irganox 1010 antioxidant 0.15 Irgafos 168 antioxidant0.15 Regalrez 1018 plasticizing resin 88.85 Kristalex 5140 strengtheningresin 0.49 Regalite 8101 plasticizing resin 2.47 Regalrez 1139plasticizing resin 2.47

[0487] The material of Example 46 was prepared by premixing thecomponents and melt blending them in an injection molding machineaccording to a example compounding method. The material was extremelytacky and readily deformable, had slow rebound and was very soft. Thespecific gravity of the material was about 0.37.

Example 47

[0488] Weight % Component Generic Class of Total Septon 4055 A-B-Acopolymer 2.35 Septon 8006 A-B-A copolymer 2.35 Kraton G 1701 A-Bcopolymer 0.47 Irganox 1010 antioxidant 0.14 Irgafos 168 antioxidant0.14 Regalrez 1018 plasticizing resin 84.36 Kristalex 5140 strengtheningresin 0.47 Regalite R101 plasticizing resin 2.34 Regalrez 1139plasticizing resin 2.34 PQ 6545 microspheres added to increase reboundrate 0.36 and decrease specific gravity Glycerin detackifying agent 4.69

[0489] The material of Example 47 was prepared by premixing thecomponents and melt blending; them in an injection molding machineaccording to a example method for compounding the example gel cushioningmaterials for use in the cushioning elements hereof. The material wasvery tacky and readily deformable, had slow rebound and littlestiffness.

Example 48

[0490] Weight % Component Generic Class of Total Septon 4055 A-B-Acopolymer 2.39 Septon 8006 A-B-A copolymer 2.39 Kraton G 1701 A-Bcopolymer 0.48 Irganox 1010 antioxidant 0.14 Irgafos 168 antioxidant0.14 Regalrez 1018 plasticizing resin 80.21+ (see premix below)Kristalex 5140 strengthening resin 0.48 Regalitc R101 plasticizing resin2.39 Regalrez 1139 plasticizing resin 2.39 Premixed 9.00 microspheres PQ6545 added to increase rebound 11.76% of microspheres rate and decreasespecific premix (1.06) gravity Regalrez 1018 88.24% of premix (7.94)

[0491] The material of Example 48 was prepared by premixing thecomponents blending them in an injection molding machine according to aexample compounding method. The material was extremely tacky and readilydeformable, had slow rebound and little stiffness. The specific gravityof the Example 48 material was about 0.63.

[0492] Pre-blending the microspheres with REGALREZ® 1018 was, in part,advantageous because it reduced the amount of microspheres that weredispersed into the air during agitation, making the microspheres easierto handle.

Example 49

[0493] A visco-elastic material was made which included four partsREGALREZ® 1018 and melt (plasticizing resin), four parts HERCULES® EsterGum I OD (plasticizing resin) and one part SEPTON 4055 (A-B-Acopolymer). The components were mixed, placed in an oven and heated toabout 300° F. After all of the components became molten, they weremixed, poured onto a flat surface and cooled. The material had littletack, deformed under pressure, was very stiff but readily deformablewith light sustained pressure, and had an extremely slow rate ofrebound.

Example 50

[0494] Weight % Component Generic Class of Total Septon 4055 A-B-Acopolymer 11.75 Ester Gum 10D visco-elasticity enhancer 35.25 Regalrez1018 plasticizing resin 29.38 Kristalex 5140 strengthening resin 1.18Foral 85 strengthening resin 3.53 LP-150 oil plasticizing oil 14.10Ethosperse LA-23 foaming facilitator 3.53 Irganox 1010 antioxidant 0.35Irgafos 168 antioxidant 0.35 Aluminum Lake Colorant 0.59 (Rocket red)

[0495] The material of Example 50 was prepared by premixing thecomponents and melt blending them in an injection molding machineaccording to a example compounding method. The material was moderatelytacky and deformable under slight, prolonged compressive force, hadextremely slow rebound and was very stiff. FORAL 85, manufactured byHercules, is a glycerol ester of hydrogenated resin that is usedprimarily as a tackifier. In the example visco-elastic gel, FORAL 85acts as a strengthening resin, and is believed to associate with andbind together the styrene domains. ETHOSPERSE LA-23, known genericallyin the art as Laureth-23, is used in the art as an emulsifier.Laureth-23 facilitates foaming in the gel materials example for use inthe cushions. The other components of Example 50 have been explainedabove.

Example 51

[0496] Component Generic Class Amount (grams) Septon 4055 A-B-Acopolymer 80.00 Septon 4 077 A-B-A copolymer 80.00 Kraton G-1701 A-Bcopolymer 16.00 Regalrez 1018 plasticizing resin 2688.00+  (seemicrosphere premix below) Irganox 1010 antioxidant  4.80 Irgafos 168antioxidant  4.80 Premixed 402.30  microspheres PQ 6545 added toincrease rebound 11.76% of premix microspheres rate and decreasespecific (47.31 g) gravity Regalrez 1018 88.24% of premix (354.99 g)

[0497] The material of Example 51 was prepared by preheating theREGALREZ® 1018, mixing all of the components except the microspherestogether, and melt blending the components in a heated vessel at 295° F.under about one to about four pounds pressure for about two hours,according to a compounding method. The mixture was then transferred toanother vessel, which was heated to about 300° F., and the premixedmicrospheres and REGALREZ® 1018 were mixed in by hand. The material wasvery tacky and readily deformable, had moderately slow rebound and wasvery soft. The specific gravity of the material of Example 51 was about0.51. Of the preceding sixteen examples (Examples 36-51), Applicantexample the material of Example 51 because of its extreme softness andslow to moderate rebound rate. Applicant also liked the material ofExample 50 because of its stiffness, but easy deformability undersustained pressure, and its extremely slow rate of reformation.

Example 52

[0498] A visco-elastic material which includes from about one to about30 weight percent of a triblock copolymer and about 70 to about 99weight percent of a plasticizer, said weight percentages being basedupon the total weight of the visco-elastic material. The visco-elasticmaterial may also include up to about 2.5 weight percent of a primaryantioxidant and up to about 1.5 weight percent of a secondaryantioxidant, said weight percentages based upon the weight of thetriblock copolymer.

[0499] The following are additional examples of formulations that can beused to make gelatinous elastomers.

Example 53

[0500] Component Generic Class Weight % of Total SEEES copolymer 75Mineral oil plasticizer 25

[0501] SEEES is used to designatedstyrene-ethyene-ethyerie-ethyene-propylene-styrene.

Example 54

[0502] Component Generic Class Weight % of Total SEEES copolymer 80Mineral oil plasticizer 20 22

Example 55

[0503] Component Generic Class Weight % of Total SEEES copolymer 83Mineral oil plasticizer 17

Example 56

[0504] Component Generic Class Weight % of Total SEEES copolymer 77Mineral oil plasticizer 23

Example 57

[0505] Component Generic Class Weight % of Total SEEES copolymer 75Mineral oil plasticizer 25

Example 58

[0506] Component Generic Class Weight % of Total SEEES copolymer 67Mineral oil plasticizer 33

Example 59

[0507] Component Generic Class Weight % of Total SEEES copolymer 60Mineral oil plasticizer 40

Example 60

[0508] Component Generic Class Weight % of Total SEPS copolymer 90Mineral oil plasticizer 10

[0509] SEPS is used to designate styrene(ethylene/propylene-)styrenewhich preferably will have a weight average molecular weight of about300,000 or more.

Example 61

[0510] Component Generic Class Weight % of Total SEPS copolymer 80Mineral oil plasticizer 20

Example 62

[0511] Component Generic Class Weight % of Total SEPS copolymer 70Mineral oil plasticizer 30

Example 63

[0512] Component Generic Class Weight % of Total SEPS copolymer 67Mineral oil plasticizer 33

Example 64

[0513] Component Generic Class Weight % of Total SEPS copolymer 60Mineral oil plasticizer 40

Example 65

[0514] Component Generic Class Weight % of Total SEPS copolymer 50Mineral oil plasticizer 50

Example 66

[0515] Component Generic Class parts by weight SEPS (4055) copolymer 80Resin (Regalrez 1018) plasticizer 10 Irganox 1010 antioxidant  0.15 2Irgaphos 168 antioxidant  0.15 3

Example 67

[0516] Component Generic Class parts by weight SEPS (4055) copolymer 10Mineral oil plasticizer 20 Irganox 1010 antioxidant 0.15 Irgaphos 168antioxidant 0.15

Example 69

[0517] Component Generic Class parts by weight SEPS (4055) copolymer 10Mineral oil plasticizer 120 Irganox 1010 antioxidant 0.15 Irganox 168antioxidant 0.15

[0518] Each of examples 67-69, while having many uses, are example foruse in causing standard prior art open cell foam, such as polyurethanefoam and latex foam rubber, to become a viscoelastic foam. This is doneby coating the open cells of the foam with a stick substance such asthat of the examples. The tacky substance should not be adhesive,however, or the foam will not return to its original shape afterdeformation. It is example that the tacky substance be a solid or a gelrather than a liquid to eliminate the need to contain the coated foam ina bladder. It is also example that the tacky substance be an elastomerso that it can flex and bend with the foam. Use of a resin as aplasticizer creates a delayed rebound viscoelastic foam. The tackysubstance, such as that of examples 67-69, can be used to coat foam byany of a variety of methods. For example, solvating the gel in a liquidand soaking the foam will work. Or the gel may be heated to become aliquid and then forced into the foam. If a foam is coated with a lowstiffness gel, then a viscoelastic foam with excellent elasticproperties is the result. Alternatively, the foam may be cut into smallpieces, the small pieces saturated with a gel, the excess gel removedfrom the gel, and the mass of gel-coated foam allowed to dry or cool sothat the gel will solidify. The gel then creates a structure holding thepieces of foam together. Such a cushioning material tends to haveexcellent elasticity and strength.

Example 70

[0519] Component Generic Class parts by weight SEPS (4055) copolymer 1Resin (Regalrez 1018) plasticizer 10 Irganox 1010 antioxidant 0.15Irganox 168 antioxidant 0.15

Example 71

[0520] Component Generic Class parts by weight SEPS (4055) copolymer 1Resin (Regalrez 1018) plasticizer 18 Irganox 1010 antioxidant 0.25

[0521] Outer coating of short rayon fibers to eliminate tackiness.

[0522] The above examples 70 and 71 provide a slow reboundviscoelastomer gel. Gel of the formula from Example 71 was formed into arectangular shape of dimensions 2 cm×2 cm×7 cm. The rebound of thematerial was then tested. When the rectangular shape was stretched alongits length (from 7 cm) to a length of 20 cm, the following was found: inone second, the gel rebounded to a length of 13 cm; in two seconds(total) it rebounded to a length of 10 cm; in four second; 3 (total) itrebounded to a length of 8 em; and in nine seconds (total) it reboundedto substantially its original shape. These slow rebound times cause theinventor to classify it as a slow rebound viscoelastomer. Similarly slowrebound was found on compression. When the rectangular shape wascompressed along its length (originally 7 cm) to a length of 3 cm, andreleased, after one second it rebounded to a length of 5 cm; after twoseconds (total) it rebounded to a length of 6 cm; after four seconds(total) it rebounded to a length of 6.5 cm, and after nine seconds(total) it returned to substantially its original shape. After fivehundred alternate compression and elongation cycles, the rectangularshaped viscoelastomer of Example 71 had substantially the samedimensions and shape as before. All of these tests were run at 25degrees 10 Clesius.

Example 72

[0523] Component Generic Class parts by weight SEPS (4055) copolymer1.64 Resin (Regalrez 1018) plasticizer 17.5 Mineral oil (Whitco LP-200)plasticizer 10 Irganox 1010 antioxidant 0.073

[0524] Outer coating of pressed-on microspheres to eliminate tackiness.

[0525] A viscoelastomer made according to the formula of Example 72 wasformed into a rectangular cube of dimensions 7 cm (width)×3 cm(height)×14 cm (length). Elongation and compression testing was thenperformed at 25 degrees Celsius and the following was found. Afterelongation of the rectangular cube along its length to a total length of30 cm, after one second it rebounded to a length of 20 cm; after twoseconds (total) it rebounded to a length of 18 cm; after four seconds(total) it rebounded to a length of 16 cm; and after nine seconds(total) it rebounded to 127 substantially its original dimensions andshape. On compression along its length to a reduced total length of 7cm, rebound was found to be as follows: after one second, the cuberebounded to a length of 10 cm; after two seconds (total) it reboundedto a length of 11.5 cm; after four seconds (total) it rebounded to alength of 13 cm; after nine seconds (total) it rebounded tosubstantially its original dimensions and shape. After five hundredalternate elongation and compression tests as just described, thematerial returned to substantially its original size and shape.

[0526] The following are viscoelastomer formulations used to reduce oilbleed and tack that was very problematic in the prior art, including inthe gels of John Y. Chen.

Example 73

[0527] Component Generic Class parts by weight SEPS (4055) copolymer 1Resin (Regalrez 1018) plasticizer 18 Irganox 1010 antioxidant 0.25

[0528] Outer coating of short rayon or other fibers to eliminatetackiness.

[0529] It is notable that the example bleed reducing additives of theseexample embodiments include a plurality of polarizable sites thereon,including halogen atoms, nitriles and others. Polarizable means anatom's ability to respond to a changing electrical field. Molecules withpolarizable atoms are more likely to be attracted to other molecules bydynamic van der Waals forces, thus reducing bleed. The bleed reducingadditives allow there to be an increase in the amount of plasticizerused in the material without an increase in oil bleed. Preferably, theelastomer will include hydrocarbon chains with polarizable groupsthereon, such as hydrogenated hydrocarbons, nitriles and others. Thepolarizable groups are believed to hold the plasticizer close to thecopolymer to reduce bleed. This occurs by the polarizable groupattracting a plasticizer at one end and an elastomer block at the other,thus maintaining association of plasticizer with elastomer. Aplasticizer can be attached to an elastomer by use of a polarizablegroup. It is example that the additive will have a plurality ofpolarizable groups. The most example bleed reducing additives arehalogenated hydrocarbon additives such as DYNAM AR PPA-791, DYNAMARPPA-790, DYNAMAR FX-9613 and FLUOROADE FC10 Flourochemical alcohol from3M Company of St. Paul, Minn. Other additives can be used to reduceplasticizer exudation. For example, FLUORORAD FC-129, FC-135, FC-430,FC-722, FC-724, FC-740, FX-8, FX-13, FX-14 and FX-189 are halogenatedhydrocarbons that will serve this purpose. Others which may be usedinclude XONTLY FSN 100, FSO 100, PFBE 8857A, TM, BA-L, TBC and FTS fromDuPont of Wilmington, Del. Witco Corp. of Houston, Tex. sellshalogenated hydrocarbons under the names EMCOL 4500 and DOSS. Hartwick,Inc. of Akron, Ohio sells chlorinated polyethylene elastomer (CPE) andchlorinated paraffin wax. None of these chemicals is marketed as a bleedreducing additive, however. It is example that processing temperaturesjust below the boiling point of the bleed reducing additive be used, aslong as that temperature will not cause elastomer degradation.

[0530] Materials of the formulas shown have been used to measure oilbleed. Percent oil bleed was measured by obtaining the combined weightof three disk shaped samples of the material, each sample having adiameter of about 3 cm and a thickness of about 6.5 mm. Two four inchsquare pieces of 20# bond paper were then weighed individually. Thethree sample disks were placed on the paper (which has high capillary orwicking action), and the other piece of paper was placed on top of thesample. The material and paper were then placed in a plastic bag andpressure sandwiched between two flat steel plates, each weighting 2285g. Next, the material samples, paper and steel plates were heated to 110degrees F. for 4 hours. Alternatively, two pieces of 12.5 cm diameterqualitative filter paper having a medium filter speed and an ash contentof 0.15%, such as that sold under the trade name DOBLE RINGS 102 fromXinhua Paper Mill may be used in place of the two four inch squarepieces of 20# bond paper. The following are example formulations.

Example 74

[0531] Component Generic Class weight percent SEPS (4077) copolymer 11.2Mineral oil (LP-150) plasticizer 87.4 FC-10 Fluorochemical alcohol bleedreducer 0.3 Saturn Yellow pigment 1.2

Example 75

[0532] Component Generic Class weight percent SEPS (4055) copolymer 12.3Mineral oil (LP-150) plasticizer 86.1 Zonyl FSN-100 bleed reducer 0.4Horizor blue pigment 1.2

Example 76

[0533] Component Generic Class weight percent SEPS (4055) copolymer 12.3Mineral oil (LP-150) plasticizer 86.1 FC-10 Fluorochemical alcohol bleedreducer 0.4 Saturn Yellow pigment 1.2

Example 77

[0534] Component Generic Class weight percent SEPS (4077) copolymer 17.9Mineral oil (LP-150) plasticizer 81.6 FC-10 Fluorochemical alcohol bleedreducer 0.5 Neon red pigment 0.9

Example 78

[0535] Component Generic Class weight percent SEPS (4055) copolymer 12.3Mineral oil (LP-150) plasticizer 86.1 Zonyl TA-N bleed reducer 0.4 BlazeOrange pigment 1.2

Example 79

[0536] Component Generic Class weight percent SEPS (4055) copolymer 14.1Mineral oil (LP-150) plasticizer 84.7 FC-10 Fluorochemical alcohol bleedreducer 0.3 Magenta pigment 0.9

Example 80

[0537] Component Generic Class weight percent SEPS (4055) copolymer 13.4Mineral oil (LP-150) plasticizer 80.2 Krator G 1701 processing additive0.3 Irganox 1010 antioxidant 0.2 Irgafos 168 antioxidant 0.2 Dynamar PPA791 bleed reducer 5.3 Magenta pigment 0.4

[0538] Examples 74-80 exhibited little or no oil bleed when tested bythe above method. The material of Example 80 lost only 0.009 percent ofits weight during bleed testing. A tackless formulation of thegelatinous elastomer may also me made according to the formula ofExample 81 and variations thereof.

Example 81

[0539] Component Generic Class weight percent SEPS (4055) copolymer24.567 Mineral oil (LP-200) plasticizer 73.701 Irganox 1076 antioxidant0.246 Irgafos 168 antioxidant 0.246 KENEMIDE E ULTRA grape seed oil-detackifier 0.246 Horizon Blue pigment 0.995

[0540] Grape seed oil or other oils and materials may be used as a slipagent or detackifier to produce an elastomer with a non-tacky exterior.

Example 82

[0541] Component Generic Class weight percent SEPS (4055) copolymer16.50 Mineral oil (LP-150) plasticizer 82.51 Irganox 17E antioxidant0.41 Zonyl BE-H detackifier 0.17 Colorant color 0.41

[0542] Example 83 below is a example formulation for making cushioningelements that may be used in mattresses.

Example 83

[0543] Component Generic Class weight percent SEPS (4055) copolymer 10Mineral oil (LP-200) plasticizer 22.5 Irganox 1010 antioxidant 0.03Irgaphos 168 antioxidant 0.03 Aluminum lake pigment colorant 0.03 ZonylBA-N fluorochemical alcohol bleed reducer 0.05

[0544] Alternative example embodiments of the gelatinous elastomer formattressing include changing the mineral oil weight percent from 22.5 tobetween 15 and 70, 15 weight percent being a firmer formulation and 70being a softer formulation. The most example gel will have a durometerof less than about 25 on the Shore A scale.

[0545] Although the gel formulations referred to above are most example,there are numerous other example gels. For example, although theyexhibit less desirable characteristics than the example gel cushioningmedia, the gel formulations of the following U.S. patent Nos. are alsouseful in the cushions: U.S. Pat. No. 5,334,646, issued in the name ofJohn Y. Chen; U.S. Pat. No. 4,369,'84, issued in the name of John Y.Chen; U.S. Pat. No. 5,262,468, issued in the name of John Y. Chen; U.S.Pat. No. 4,618,213, issued in the mane of John Y. Chen; U.S. Pat. No.5,336,708, issued in the name of John Y. Chen, each of which isincorporated by reference in its entirety. Other oil-extendedpolystyrene poly(ethylene/butylene)-polystyrene gels can be usedadvantageously for the cushions hereof. For example, the GLS Corporationof Cary, Ill. offers a gel in injection moldable pellet norm under thedesignation G-6703 which is made with the ingredients of the gelsmentioned above but with less plasticizing oil, and has a Shore Ahardness of 3. Other example gels which may be used include PVCplastisol gels, silicone gels, and polyurethane gels.

[0546] PVC plastisol gels are well known in the art, and are exemplifiedby artificial worms and are also cheaper to make than thicker walledlower durometer cushions. And if the gel is used as a shoe insert, thenthe example gels just described will be superior because the gel willnot tend to flow out from under the foot being cushioned (or otherobject being cushioned) as it would grubs used in fishing. A descriptionof a typical PVC plastisol gel is given in U.S. Pat. No. 5,330,249issued in the name of Weber et al. on Jul. 19, 1994, which is herebyincorporated by reference. PVC plastisol gels are not the most examplebecause their strength is not as high for a given gel rigidity as theexample gel media or even the gels of the Chen patents, but they areacceptable for use.

[0547] Silicone gels are also well known in the art, and are availablefrom many sources including GE Silicones and Dow Corning. From aperformance standpoint, silicone gels are excellent for use herein.However, the cost of silicone gels is many times higher than that of themost example gels.

[0548] Also in the most example gels, the ratio of plasticizer such asoil to triblock copolymer is 3:1 or less (such as 2.5:1; 2.0:1; 1.5:1;and 1.0:1.0). At these ratios, the gel is not stirable during themelting process and is not castable when melted. Thus this gel is notsuitable for typical prior art manufacturing such as that proposed inthe John Y. Chen patents. However, the inventor has found that these lowratios of plasticizer to copolymer have very high strength, superiorshape retention, lower tack, and lower bleed-out properties than theprior art. They also have a higher durometer than the prior art.Cushioning devices, such as hollow column gel cushions, can be made muchlighter if the walls are thin and of a high durometer. Such cushionswith prior art gels such as those of John Y. Chen. Finally, gels ofthese formulations exhibit much better processability through screws,such as the compounding screws of extruders and injection moldingmachines. The prior art Chen gels do not feed through screws wellbecause they are too slippery in the pre-mix state and are not drivenwell by screws because their viscosity is too low. The gels have ahigher viscosity and perform much better when pushed by a screw such asin an injection molding machine or in an extruder.

[0549] Polyurethane gels are also well known in the art, and areavailable from a number of companies including Bayer Aktiengesellschaftin Europe. For reference, the reader is directed to U.S. Pat. No.5,362,834 issued in the name of Schapel et al. on Nov. 8, 1994, which ishereby incorporated by reference, for more information concerningpolyurethane gels. Like silicone gels, polyurethane gels are excellentfrom a performance standpoint, but are many times more expensive thanthe most example gels.

[0550] Foam rubber and polyurethane foams may also be useful ascushioning media in the cushioning elements, so long as they exhibitgel-like buckling behavior. Preferably, in order to exhibit desiredbuckling and elastomeric or visco-elastomeric gel-like behavior, columnwalls formed from polyurethane foams and foam rubbers are very thin.Alternatively, thicker column walls formed from polyurethane foams andfoam rubbers may also exhibit the desired buckling and gel-likecharacteristics with appropriate column shapes and column patternconfigurations. Foam rubbers and polyurethane foams are useful in thecushioning element if columns occupy about one-half or more of thecushion volume. Cushion volume is defined by the top and bottom surfacesand the perimeter of the cushion.

[0551] C. Method for Making the Cushions

[0552] There are several ways in which the cushion can be manufactured.

[0553] 1. Injection Molding

[0554] The cushions can be injection molded by standard injectionmolding techniques. For example, a cavity mold is created with coresinside the cavity. The gel ingredients are heated while stirring, whichturns the gel into a liquid. The liquid is injected into the cavity andflows around the cores. The material is allowed to cool, which causes itto solidify. When the mold is parted, the cores pull out of thesolidified gel and leave the hollow columns. The cushion is removed fromthe cavity, the mold is closed, and liquid is injected to form the nextcushion, this process being repeated to manufacture the desired quantityof cushioning elements. This results in very inexpensive cushioningelements because the example gel is inexpensive and the manufacturingprocess is quick and requires very little labor.

[0555] Referring to FIG. 4, an example mold in use is depicted. The moldassembly 401 has a first mold half 401 and a second mold half 404. Thesecond mold half 404 has a cavity 408 and a base plate 405 at the bottomof the cavity 408. It also has side walls 414 and 415. The first moldhalf 402 has a core mounting plate 409 and a plurality of cores 403mounted on it in any desired spacing, and arrangement. The cores 403 maybe of any desired shape, such as triangular, square, pentagonal, n-sided(where n is any integer), round, oval or of any other configuration incross section in order to yield a molded cushioning element 406 of thedesired configuration. The cores 4,03 could also be tapered from a morenarrow dimension (reference numeral 410) at their end distal from thecore mounting plate 409 to a wider dimension (reference numeral 411) attheir end proximal the core mounting plate. This would create a taperedcolumn or tapered column walls so that the radial measurement of acolumn orthogonal to its longitudinal axis would be different at twoselected different points on the longitudinal axis.

[0556] Alternatively, the cores 403 could be tapered from 410 to 411,stepped from 410 to 411 or configured otherwise to create a column ofdesired shape. Use of the hexagonal cores 403 depicted yields acushioning element 406 with cushioning media 412 molded so that thecolumn walls 413 form the hollow columns 407 in a hexagonalconfiguration.

[0557] When the first mold half 402 and second mold half 404 are broughttogether, core distal ends 410 abut the second mold half base plate 405.This prevents liquid cushioning media from flowing between the baseplate 405 and the core distal ends 410 in order to achieve a cushioningelement 406 which has hollow columns through which air can circulate. Ifthe core distal ends 410 did not reach all the way to the base plate408, then the columns 407 would be open at one end and closed at theother.

[0558]FIG. 5 depicts an alternative mold configuration. The moldassembly 501 includes first mold half 502 that includes a first coremounting plate 509 onto which a plurality of cores 503 are mounted in adesired configuration. The cores 503 each have a core proximal endproximal to the core mounting plate 509 and a core distal end 511 distalto the core mounting plate 509. The mold assembly 501 also includes amold second half 504 which has a core mounting plate 505, side walls512, and cores 508 each having a core proximal end 513 proximal to thecore mounting plate 505 and a core distal end 514 distal to the coremounting plate. The second core half 504 also has a cavity 514 in whichits cores 508 are found. The mold assembly 501 may be designed so thatwhen the two mold halves are brought together the core distal ends abutthe surface of their opposing core mounting plates. This produces acushioning element 506 with hollow columns 507 that are open from oneend to the other in order to maximize air circulation through thecolumns 507 and yieldability of the cushioning element 506.Alternatively, the mold assembly 501 may be designed so that the coredistal ends do not contact the core mounting plates. This will result ina cushion having a cross sectional appearance like that depicted in FIG.6, where the columns are shorter in length than the thickness of thecushioning element, so the columns are closed at one end.

[0559] In the prior art, such the John Y. Chen gel patents and in U.S.Pat. No. 5,618,882, the example method for manufacturing gel articleswas casting, and the example method for making the gel was meltblending. These prior art manufacturing methods are slow, expensive,messy and inefficient.

[0560] The applicant has learned how to manufacture gel articles usinggels of the example formulations and other formulations by filling ahollow cavity in a mold with the gel. A mold with a hollow cavity ofappropriate shape for the article to be made is first obtained. Then aquantity of gelatinous elastomer or viscoelastomer is obtained, or theingredients for making it are obtained. Then the gelatinous elastomer orviscoelastomer or the ingredients are fed into a compounding screw (suchas a single screw or a twin screw) of an appropriate machine such as aninjection molding machine or an extruder. Then the screw moves the gelalong its length under temperature and pressure. Then the screw movesthe gel into a cavity of a mold in order to fill the cavity of the moldand create a molded gel article. With this manufacturing method, thematerials of the gel are exposed to heat for a much shorter time thanprior art manufacturing methods, resulting in less elastomerdegradation. The materials of the gel are also exposed to heat for ashorter period of time. And because the gel can be forced into the moldunder pressure rather than relying on gravity flow for casting, articlesof a wide variety of shapes can be made and articles can be made withthe use of little plasticizer, resulting in much stronger gels.Alternatively, instead of injecting the gel material into the mold, itcan be allowed to flow into the mold under its own weight.

[0561] 2. Extrusion

[0562] The cushioning elements may also be manufactured by typicalextrusion processes. If extrusion is used, hot liquid gel is forcedthrough an extrusion die. The die has metal rods situated to obstructthe path of the gel in some locations so that the gel is forced throughthe die in a pattern resembling the desired shape of the finishedcushioning element. Thus the die, having an aperture, an apertureperiphery, and forming rods within the aperture has an appearancesimilar to that of the desired cushioning element except that theportions of the die that are solid will be represented by empty air inthe finished cushion, and the portions of the die in the aperture thatare unobstructed will represent gel in the finished cushioning element.Thus the rods of the die should be of the shape and size that thedesired cushioning element is intended to be; the spacing of the rodsshould approximate the spacing of the columns that is desired in thefinished cushioning element; and the shape and size of the apertureperiphery should approximate the shape and size of the periphery of thedesired cushioning element.

[0563] When gel is forced through the die, the liquid gel is cooledduring its traverse through the die, causing it to solidify as it leavesthe die. The gel is then cut at desired length intervals to formcushioning elements. Of course, cushioning elements so formed havehollow columns throughout their length, although the ends of the columnscould be sealed as mentioned elsewhere herein. It is not expected,however, that extrusion is a practical method for manufacturing cushionswith columns that vary in dimension along their length. The extrudedcushioning element is very inexpensive because the both the cushioningmedia (i.e. the example gel) is inexpensive and the manufacturingprocess is highly automated so that labor requirements are very low.

[0564] Alternatively, a single tube may be extruded, then cut to alength that will form the appropriate cushion thickness. The tubes arethen bonded together to form a cushioning element. Referring to FIG. 41,a example embodiment of a cushion 4101 which is made from. bonded tubes4102 a, 4102 b, 4102 c, etc. is shown. Each tube includes a hollowcolumn 4103 formed by a column wall 4104. Preferably, column wall 4104is made from a gel cushioning medium 4105, such as the exampleelastomeric or visco-elastomeric materials for use in the cushions.

[0565]FIG. 42 illustrates an example of a example method for bonding twotubes 4102 a and 4102 b together. Heating cores 4201 and 4203, whichpreferably include a heating edge 4202 and 4204, respectively, arepositioned in tubes 4102 a and 4102 b within corners 4110 a and 4110 b,respectively, such that edges 4202 and 4204 abut the inner surface ofthe corners. Preferably, cores 4201 and 4203 hold the outer surface ofcorners 4110 a and 4110 b against one another.

[0566] Preferably, securing cores 4205 and 4206 are positioned in eachof the two inner corners formed by tubes 4102 a and 4102 b to securecorners 4110 a and 4110 b from sliding side-to-side in relation to oneanother. Preferably, heating edges 4202 and 4204 are heated to atemperature sufficient to melt cushioning medium 4105, but not to atemperature which would burn the material. As heating edges 4202 and4204 are heated to a desirable temperature, the cushioning mediumlocated in corners 4110 a and 4110 b melts. Preferably, heating edges4202 and 4204 remain heated until all of the material located at corners4110 a and 4110 b becomes molten and fuses tubes 4102 a and 4102 btogether. Heating edges 4202 and 4204 and corners 4110 a and 4110 b arethen cooled. Preferably, heating edges 4202 and 4204 are each coveredwith a non stick surface 4207 and 4208, respectively. Similarly,securing cores 4205 and 4206 also have non-stick surfaces 4211 and 4212.The non-stick surfaces prevent the securing cores 4205 and 4206 andheating edges 4202 and 4204 of heating cores 4201 and 4203 from stickingto the cushioning medium located at corners 4110 a and 4110 b as themedium becomes molten. A example non-stick surface is Teflon paper.Cores 4201, 4203, 4205 and 4206 are then removed from tubes 4102 a and4102 b.

[0567] In the example extrusion method, the elastomer gel ispre-compounded at a temperature of about 470 degrees Fahrenheit. Thenthe gel is run through an extrusion die at a example temperature ofabout 425 degrees Fahrenheit. The pressure in the extrusion die may befrom 200 to 4001) pounds per square; inch, depending on the gel beingextruded and the die dimensions and characteristics. The formulation ofthe gel will affect desired temperature. The part may be extruded from adie into water to aid in cooling and solidifying the gel. The gel may beextruded upwards through a die and into water of necessary to maintainthe shape of the extruded part.

[0568] The same advantages and techniques for using a screw to compoundor simply melt gel material and force it into a mold from an injectionmolding machine can be applied to an extruder, using the extruder screwto compound the gelatinous material and force it through a die. Thuslarger, more complex and stronger parts can be made when the extrusionmethod is used than if prior art casting is used.

[0569] 3. Casting

[0570] Another manufacturing process by which the cushioning element canbe made is by generally known casting technology. In order to cast thecushioning element, hot liquid gel (or other cushioning media) is pouredinto an open cavity, and an assembly of metal rods is pushed into theliquid. The rods will form the columns of the finished product. Theliquid flows between the metal rods, cools and solidifies. The metalrods are then removed, leaving; the hollow portions of the columns, andthe cushion is removed from the cavity. A vibrator may be used tovibrate the cavity to facilitate the flow of the liquid between the rodsif needed.

[0571] With reference to FIG. 42, in an alternative casting process,about half of the column forming rods have a plurality of protrusionsextending therefrom. Preferably, each of the rods which are adjacent toa rod which has protrusions extending therefrom do not includeprotrusions therefrom. The example protrusions extend toward each of theadjacent rods and substantially across the distance between the adjacentrods. As cushioning medium is cast using this process, the rods withprotrusions preferably create fenestrations in the column wall whichsurrounds the column created thereby, each of the fenestrationspreferably passing substantially through the column wall to an adjacentcolumn. FIG. 42 shows one example configuration of fenestrations 4200,having a circular shape. Other shapes such as diamonds, squares,triangles, or others are also useful as fenestrations. After thecushioning medium has solidified, the rods which lack protrusions arepreferably removed from the cushioning element first. The rods withprotrusions are then removed from the cushioning medium, which, due toits softness and elastomeric or visco-elastomeric properties, giveseasily without tearing or breaking as the rods are removed.

[0572] Casting is a more labor intensive manufacturing method thaninjection molding or extrusion, but the tooling is generally lessexpensive, especially for large cushions. This is the example method ofmaking very large cushions, such as king-size bed mattresses, since thesize of such cushions is greater than that which can be manufacturedusing injection molding or extrusion methods.

[0573] 4. Two Step Manufacturing Process

[0574] In many instances it is advantage to prepare the gelatinousmaterial in advance and manufacture a product from it at a later date.The inventor has implemented a process for doing this that has verybeneficial qualities for the manufacture of gel products.

[0575] The first step is to manufacture the gelatinous elastomer. Thisis done by gathering appropriate ingredients, as described in detailabove, and appropriate equipment for compounding the elastomer. Whilemelt blending and solvent blending are possible, it is much example touse either a single screw or a twin screw compounder such as those foundon extruders and injection molding machines. The ingredients for the gelare fed into the screw at one end, and as the screw moves theingredients along its length under pressure and temperature, compoundingof the ingredients takes place (such as association of the plasticizerwith the elastomer molecules and association of the bleed reducingadditive with both the plasticizer and the elastomer molecules). As thecompounded gel exits the screw, it may then be cut or chopped into smallpieces or pellets.

[0576] The pellets can be stored (such as in bags or barrels),transported and later used. In the later use, the second step isperformed. I it, the pellets are melted in order to injection mold,extrude, cast or spray a final product with the gel. It is example thatthe pellets will be melted again under pressure in a screw such as thatfound on an injection molding machine or extruder.

[0577] There are distinct advantages to this two step process. First, inthe first process step the lower molecular weight fractions (volatiles)of the plasticizer (such as mineral oil) are boiled off. Thus, in thesecond step there is no boiling of the plasticizer and voids in themanufactured part are reduced. Quality of the finished product andstrength of the finished product are thus greatly enhanced.

[0578] Another advantage is that some screws have difficulty grabbingand transporting the ingredients of the gel because they are slipperyand coated with oil, but the screw can easily grab and push thepreformed pellets. Thus, the use of pre-formed pellets allows the use ofa much shorter screw and shorter processing times and shorter exposureto high temperatures. Although the example method for this embodimentincludes running the gel through the screw twice, any compounding methodmay be used twice on the same gel in order to achieve good results. Itdesirable, the pellets can be extruded underwater or fall into water forinstant cooling, or spread out on a stationary or moving surface for aircooling.

[0579] D. Other Cushioning Devices

[0580] 1. Cushions Comprising End-Supported Free-Standing BucklingElastic Members, and Methods for Manufacturing the Same

[0581] As used herein, cushions are defined as pads of any shape whichequalize or redistribute pressure over the surface of an item whichbears on the pad, which soften the surface on which the load from theitem bears, which absorb or attenuate vibration and/or shock to protectthe item, and/or which provide: a resilient action to separate the itemfrom the movements of its surroundings. More specifically, thisembodiment is for a cushion which achieves these cushioning featuresthrough the buckling action of end-supported free-standing bucklingelastic members, and does so in a manner which provides advantages overprior art cushions.

[0582] The inventor intends to obtain the advantages of buckling columnperformance with foam, which is lightweight and inexpensive and bondsreadily to other materials. Unfortunately, sculpted foam compresses an asingle unit rather than buckling under point load. The embodimentdescribed below achieves advantages of gelatinous buckling columns butwith light weight and low cost.

[0583] This embodiment is a cushion comprising one or more free-standingbuckling members which are supported at or near the ends. These bucklingmembers are configured to sustain a given level of compression loadingfrom the cushioned item resulting in compression deformation withoutbuckling, and then if that given level of compression loading is exceed,to buckle and undergo further deformation with less than a linearlyproportional increase in loading. A rail is supported at the ends inthat it is tied into an overall supporting structure at each end of thebuckling portion of the member. The rail is allowed to continue beyondthe buckling portion. Free-standing indicates that a buckling portion ofthe member is not integrally connected to another member or to anothersupport structure other than at or near the ends, thus allowing freebuckling. One or more portions of the member can be connectednon-freestanding, so long as at least one buckling portion is freestanding. The buckling members can be solid or hollow.

[0584] The degrees of buckling freedom of the buckling members of thecushion can be one or more. For example, a round column can buckle inany lateral direction, so it has unlimited degrees of freedom. As asecond example, a column of square cross-sectional shape buckles moreeasily in two orthogonal directions than in other directions, so iteffectively has two degrees of freedom. As a third example, a rail whichis 1 inch thick, 5 inches tall, and 30 inches long and attached to asupport at each end of the 30-inch length is most likely to buckle in adirection transverse to the length; thus it effectively has one degreeof freedom. This embodiment is not limited to any particular membershape or configuration so long as it meets the criteria set forth above.

[0585] Neither is this embodiment limited to the specific material ofconstruction. Any material which is elastic or visco-elastic in nature,meaning that when load is removed it will quickly or at least eventuallyspring back to about the original shape and size, and which is durableenough to meet the operating conditions of the cushion, will work.

[0586] Steel meets this criteria, and is particularly useful in the formof coil springs. Compressible coil springs can form the bucklingmembers. The spring should be sized (wire diameter, wrap diameter, wrapdensity, etc.) so that it's overall length-to diameter ratio results ininstability when loaded at less than or equal to the maximum desiredlocalized cushioning load, and so that the compression of the spring inthe pre-buckle loading is acceptable for the given cushioningrequirement. For example, in a mattress or any other cushion for thehuman body, it is desirable that the cushion be able to support apressure load of at least 20 mm of Hg, but never over 32 mm of Hg (thecapillary shut-off pressure in at-risk individuals). The spring shouldthen be designed so that when 20 mm of Hg is applied over the area ofthe cushion supported by that spring, the spring compresses withoutbuckling, but when 25 mm of Hg are applied over the same area, thespring buckles. The ends of the free-standing coil springs can besupported by being inter-laced in a network of criss-crossing lateralsprings, much as is done in spring units of prior art mattresses. Thedifference between the springs of my cushion and the prior-art mattressspring units is that prior art springs are designed to be stable againstbuckling and only compress when loaded, whereas the springs are unstableand will buckle if overloaded.

[0587] Elastomers such as rubbers, oil gels, silicones, polyurethanes,plastisols and the like will also work. Unlike the gel hollow-columnshared-wall cushions described above, however, the buckling membershereof must be free standing.

[0588] Flexible open-cell polyethylene-based polyurethane foams, such asis widely and commonly used in the furniture and mattress industry, workwell. One of the characteristics is that a foam cushion with bucklingmembers is considerably softer overall than a cushion of the samedimension made of ‘solid’ foam. Thus, a much stiffer, denser foam can beused with the same overall cushion durometer, and since denser foams aremuch stronger and more durable than lighter foams, the overalldurability of the cushion can be greater than the ‘solid’ foam cushionbeing replaced with the cushion. A unique process for fabricating foamcushions with buckling members which has low labor requirements andminimal waste, thus keeping cost to a minimum is disclosed. Thisprocess, along with the embodiment in two types of foam cushions, areillustrated by the following examples. These examples are by way ofillustration, and should not be construed as limiting.

[0589] The first example is as follows. A bun (such as 30″ high, 80″long, 60″ wide) of high resiliency polyether-based polyurethane flexiblefoam is purchased from a foam manufacturer, with an ILD of 50 and adensity of 2.8 pounds per cubic foot (considered very durable). A solidfoam mattress with an ILD of 50 would be much too firm for the typicalconsumer. However, the cushion of this example is much softer than a‘solid’ slab of 50 ILD foam. FIG. 43 shows a cutting pattern 4301. Eachdashed line 4302 shows a cut all the way through the width of the bun(i.e., into the paper). These cuts are made by a CNC reciprocal saw suchas is made by Baumer USA and is well known in the art. The bun is thenturned 90 degrees and cut in a similar fashion as shown in FIG. 44 usingits cutting pattern 4401. When the bun is disassembled as shown in FIG.45, and the thin disconnected sections are removed, the resulting foampieces 4501, 4502, 4503, 4504, 4505 and 4506 are bonded together withany of several common foam adhesives to result in the mattress core 4601of FIG. 46. FIG. 47 depicts foam side support pieces 4701 having beeninserted into receptacles 4702 in all four sides of the foam unit 4703.A cover can then be applied by methods well known in the art. Themattress core has one-piece foam skins which are integral with and whichsupport the many square cross section free standing columns of squarecross section within the core.

[0590]FIG. 48 shows half of the mattress core 4801 before bonding to theother half, illustrating the individual square half-columns. Thehalf-columns become full columns when the piece is bonded to a likepiece of opposite orientation. This mattress cushion is capable of highlocal deformations due to the buckling of the square columns within thecushion. A person lying on his side on this mattress has the feelingthat there is no significant pressure on his hips or shoulders, but thathis torso is receiving sufficient pressure that sagging of the back doesnot occur.

[0591] The second example is as follows. A bun (such as 30″ high, 80″long, 60″ wide) of high resiliency polyether-based polyurethane flexiblefoam is purchased from a foam manufacturer, with an ILD of 50 and adensity of 2.8 pounds per cubic foot (considered very durable). FIG. 51shows a example cutting pattern 5101. Each dashed line shows a cut allthe way through the width (into the paper). These cuts are made by a CNCreciprocal saw such as is made by Baumer USA and is well known in theart. This is a simpler pattern, and quicker to cut, than theillustration of the previous example. As a further contrast to theprevious example, this bun is cut from only one direction rather thanturned 90 degrees and cut a second time. When the bun is disassembled asshown in FIG. 52, very little is discarded. The resulting foam pieces5201 5212 are bonded together as shown in FIGS. 52 and 53 with rails5201 and 5202 being bonded with any of several common foam adhesives toresult in the mattress core of the previous example. A cover is thenapplied. The mattress core has one-piece foam skins which are integralwith and which support the foam free-standing rectangular rail withinthe core. These are the type of rails described above as effectivelyhaving one degree of freedom. While this may reduce the overalleffectiveness of the cushion compared to buckling members with multipledegrees of freedom, it is still effective and results in a lessexpensive mattress to produce because cutting time is reduced and wasteis minimized.

[0592] This mattress cushion is capable of high local deformations dueto the buckling of the rectangular rails within the cushion. A personlying on his side on this mattress has the feeling that there is nosignificant pressure on his hips or shoulders, but that his torso isreceiving sufficient pressure that sagging of the back does not occur.FIG. 54 shows how the rail members 5402 buckle 5401 under the moreprotruding parts of the body 5401.

[0593] Buckling members, because they do not support load effectively,also do not transmit vibration, shock, or movement effectively. Thus thecushions are effective in cushions which have such requirements.Further, the cushions are softer than cushions made from the same typesof materials without buckling columns. In part, this is because materialis missing around my free-standing buckling members. But moresignificantly, the cushions are able to locally deform without draggingdown the surrounding material to the extent that ‘solid’ cushions do.

[0594] The cushions hereof, as illustrated but not limited to theexamples above, create a cushion different from and superior to theprior art in several ways. The cushions are very effective at pressureredistribution and equalization because the buckling member areincapable of taking more than their area share of the load, andsurrounding members pick up the load that is ‘refused’ by the buckledmembers. The cushions are effective at absorption/attenuation ofvibration, shock, and movement because buckled columns do not transmitthese as well as ‘solid’ material or structurally sound members. Thecushions are very soft because they allow local deformation with lessdragging down of the surrounding material. Unlike elastomericcompression cushions, my cushions do push back in linear proportion tothe deformation of the cushion; thus pressure hot-spots are minimized,and support is even (e.g., back doesn't sag on a mattress). Unlikebladderized flowable-medium cushions, the cushions cannot leak, are verylight weight, are low cost, have less tendency to crush down over time(because higher density foams are usable), and has no hammocking andtherefore none of the associated problems. Unlike cushions comprisinghollow gel columns with shared walls, these cushions are very lightweight, less expensive to produce, and bond well to other cushioncomponents (e.g., a mattress cover or furniture cushion cover).

[0595] 2. Methods and Apparatuses for Providing Border Stiffness Arounda Cushion

[0596] This embodiment is in the area of methods of cushion borders.More specifically, this embodiment includes methods and apparatuses foradvantageously and economically stiffening the edges of hollow-columnedlow-durometer elastomer cushions (such as described above) whileproviding lateral tension on the elastomer structure.

[0597] Gelatinous hollow-columned low-durometer elastomer cushions suchas those described above make very effective cushions by equalizingpressure across an uneven person or object. Unfortunately, thesecushions are not very laterally stable especially when made with thinwalled hollow columns. They are more stable when the column walls are atleast one third of the column width, but the weight and cost are muchtoo high for most practical applications. When a more practicalthin-wall hollow column configuration is used, the cushion easilycollapses sideways. A need thus exists for a border which will keep thehollow column from collapsing laterally. Practical experiments withhollow column have also shown that if a small degree of lateral bi-axialtension is applied to the hollow column (in other words, it is kept abit stretched out so it is tight), it is more effective in providinggood support and pressure equalization.

[0598] Another problem with thin-wall hollow column cushions,particularly in mattress applications, is that when the columnscollapse, only a small portion of the original height remains. Sittingon the edge of a mattress thus leaves the sitter feeling unsupported andperhaps unstable. A need exists for a border for hollow column cushionsincluding but not limited to mattresses which will be more substantialfor needs including but not limited to sitting.

[0599] This discussion will focus on mattresses as typical, but thisapplies to all hollow-column cushions. The mattress industry hasdeveloped many borders. For example, a classic waterbed has woodensides. A “foundation” waterbed, which appears more like a traditionalmattress, has a very stiff flexible open-cell polyurethane borderseveral inches wide around the entire perimeter of the water bladderarea, inside the cover. It must be stiff—unacceptably stiff—because itis not attached mechanically to the inner water bladder(s), and even ifit was they would provide little support. Spring mattresses are made ofcoil springs joined at their tops by smaller diameter lateral coilsprings, and do not provide sufficient edge support by themselves.Manufacturers of spring mattresses thus use well known border systemswhich included edge wires and edge clips and other known devices tostiffen and strengthen the edges of the mattress. Manufacturers of latexfoam rubber mattresses often put a border of polyurethane foam aroundthe perimeter of the latex core before applying the cover, in a mannerknown as a “racetrack”. The foam is stiffer than the floppy latex, butnot so stiff as to be uncomfortable as with the foundation waterbedmattresses.

[0600] An open-cell flexible foam border would be very acceptable on theperimeter of a hollow column mattress core within a mattress cover.Unfortunately, unlike with a latex foam rubber core, the foam cannot beglued to the hollow column gel because the oil component of the gelprevents reliable bonding with known practical adhesives. It would notbe desirable to use a very stiff foam as with the foundation waterbedmattresses, because they are uncomfortable. Thus a method is needed toeconomically and reliably attach a foam border to a hollow column gelcushion perimeter. A further need exists for a method to providesufficient stiffness to the border to pre-tension the hollow columnlaterally without ruining the sitting feel of the border.

[0601] This embodiment is to encapsulate one or more outer cell walls ofa hollow-column buckling cushion within a border material or group ofmaterials so as to physically interlock the hollow column gel and theborder. Added features are (1) means to prevent the border so formedfrom being taller than the hollow column gel by removing a portion ofone or more exterior cell walls in the hollow column gel to allow theborder material(s) to be continuous across what would otherwise be solidelastomer wall and (2) to reinforce the border with another member whichwould allow lateral pre-tensioning of the hollow column gel withoutputting so much lateral load on the border material(s) as to bend theborder beyond desirable limits. This is best illustrated by means ofexamples, which are not to be interpreted as limiting the abovedescription in any way.

[0602]FIG. 55 shows a 6″ tall hollow column gel mattress core 5501. Themattress core 5501 includes foam pieces 5502 stuffed into each outerperimeter cell of the hollow column gel. They are adhesively bonded toan exterior piece of foam through holes 5503 punched in the hollowcolumn gel outer walls. The inner and outer foam pieces are optionallyfurther joined by a cap top and bottom 5504 and 5504, in this case madefrom foam felt. A fiberglass rod 5506 is inserted through holes punchedin the interior walls of the hollow column gel and through the foampieces stuffed into the outer cells. This rod does not overly interferewith the sitting comfort of the cushion because it is buried so deeplyin the soft foam of the border. The rod is very stiff and thus allowslateral pre-tensioning of the hollow column gel. The rod is joined toother rods around the periphery by lugs at the four corners of thehollow column gel.

[0603] Another example is depicted in FIG. 56. That figure shows theconfiguration of FIG. 55 but with an additional layer of softer“pillow-top” style hollow column gel atop the stiffened 154 hollowcolumn gel mattress core. The encapsulation of the hollow column gelsides within the foam border 5602 involves several perimeter rows ofcells, and keeps the hollow column gel pillow-top 5601 securely in placeso that it cannot collapse laterally.

[0604]FIG. 57 depicts a configuration similar to that of FIG. 56 butwith two “pillow-top” hollow column gel layers 5701 and 5702encapsulated within the foam border.

[0605]FIG. 58 shows a border configuration made from two pieces of foamper side of the mattress core. A hollow column gel cushioning element5801 is provided with fiberglass rods 5802 as discussed. A first foamborder layer 5803 and a second foam border layer 5804 are provided forborder stiffness. This is anticipated to require less labor input thanthe individual cell foam pieces of the prior examples because there areless pieces to handle. This requires that the pieces be continuousacross the first hollow column gel cell wall. The cell walls were thusbeveled 5805 as shown to allow this continuity.

[0606]FIG. 59 shows the configuration of the previous example but withan additional layer of softer “pillow-top” style hollow column gel 5901atop the mattress core 5801. The encapsulation of the core 5801 sideswithin the foam border 5903 and 5804 keeps the pillow top layer 5901securely in place so that it cannot collapse laterally, and does notincrease the number of foam pieces needed.

[0607]FIG. 60 shows a fixture 6000 which assists in installing the foampieces of the previous two examples. Without such a fixture, it isdifficult to get the adhesive-coated foam uniformly into the outer rowof hollow column gel cells. FIGS. 60a and 60 b show the fixture 6000with the foam 6001 inserted and not inserted respectively. FIGS. 7, 8,and 9 show the method used in conjunction with this fixture. FIG. 61depicts the fixture 6000 in use with the foam 6001 being inserted intothe fixture so that the slit foam is inserted into the hollow column gel6003 cells. The foam and the hollow column gel should be glued forassembly. When the fixture is removed, the foam will expand to fill thehollow columns of the hollow column gel, keeping the pieces assembleduntil the glue can dry.

[0608]FIG. 62 shows a. method for use in conjunction with the foamborder hereof to allow lateral pre-tensioning of the hollow column gelwithout a fiberglass rod. A layer of foam which spans the entire hollowcolumn gel mattress core surface is bonded to the border form on thebottom of the mattress core, and optionally on the top as well. Thus,there is a hollow column gel core 6201 with a layer of foam on top andbottom 6205 a and 6205 b, and a layer of foam 6202 and 6203 around theouter periphery of the hollow column gel. This ensures that the userwill not feel anything hard as may happen with the fiberglass rod. Whenthe weight of the mattress core descends on this foam layer, it willgently force it to be straight, keeping the foam border, which is bondedto it, from bending in from the lateral tension on the hollow columngel. The foam layer(s) have the added advantage of making ‘bottomingout’ through the hollow column gel more comfortable experience when, forexample, kneeling on the bed.

[0609]FIG. 63 shows a hollow column gel ‘pillow-top’ 6301 that can belaid over any mattress regardless of construction. It uses a hollowcolumn gel core 6302 and a foam border 6303 that consists of pieces offoam stuffed into the outer two rows of cells of the hollow column geland bonded to an exterior piece of foam by means of a bridging member.This border assembly is then glued into a fabric cover 6304, which ishook-and-loop attached to the mattress below so that the hollow columngel can be pretensioned.

[0610]FIG. 64 shows a pillow-top of hollow column gel 6401 similar tothat of the previous figure except that it has two layers of hollowcolumn gel 6402 and 6403 pillow-top material. The devices are notlimited to any particular border material or hollow column gel material.

[0611] The key features are to encapsulate one or more outer cell wallsof a hollow-column buckling cushion within a border material or group ofmaterials so as to physically interlock the hollow column gel and theborder. Added features are (1) means to prevent the border so formedfrom being taller than the hollow column gel by removing a portion ofone or more exterior cell walls in the hollow column gel to allow theborder material(s) to be continuous across what would otherwise be solidelastomer wall and (2) to reinforce the border with another member whichwould allow lateral pre-tensioning of the hollow column gel withoutputting so much lateral load on the border material(s) as to bend theborder beyond desirable limits. While open-cell flexible polyurethanefoam is the example border material, other materials could be used,including wood, air bladders, metal, plastic, closed cell foams, latexfoams, rubber, synthetic elastomers in solid or hollow configurations,etc. Rigid members of any type may be used in place of the examplefiberglass rods, including metal, wood, plastic, etc. Flexible membersof any type may be used in place of the example open-cell polyurethanefoam layer that spans the mattress surface, including thermoplasticfilms, elastomer films, rubber sheets, closed cell elastomeric foamsheets, felt, reticulated foam, etc.

[0612] 3. Rigid, Collapsible Mattress Foundations

[0613] This is in the area of foundations for conventional bedmattresses and other mattresses of similar construction. Morespecifically, this relates to a foundation, for use in supporting aconventional mattress such as an innerspring or foam mattress, whichcollapses to ship in a more compact fashion to save shipping costs, hasexceptional durability and function, and provides a non-slip mattressinterface surface, and for methods of making such foundations.

[0614] Mattresses and foundations are often bought in sets at retailfurniture stores. The foundation (sometimes called a box spring) isgenerally to be set into a steel angle-iron frame or frame of othermaterials such as wood. The frame holds the foundation off the floor.The foundation in turn supports the mattress, which is usually aseparate piece. The mattress's main function is to provide cushioning ina supportive manner, and typically contains springs, foam, fiberbatting, and the like. The foundation's main function is to providesupport for the relatively floppy mattress so that the mattress does notsag. Another function is to lift the mattress to a proper height foregress, ingress, and sitting.

[0615] Prior art foundations are made in a number of ways. Designers offoundations have several criteria. First is the structural stiffnessnecessary so that the mattress cannot sag overall nor have local bulkdeformation. Second is the creation of space sufficient to lift themattress to the proper height; foundations are often in the 7″ to 8″high range. Third is aesthetics, wherein it is desired that thefoundation has upholstery that matches the cover of the mattress. Fourthis to meet the first and second, and optionally the third, criteria atthe absolutely lowest costs. This fourth criterion often compromises thefirst two or three. Foundations are often made which have inadequatestructural support in the bulk and/or local sense, or which have fabricsover the top or bottom which rip easily. Foundations are often made byattaching metal wire structures to a grid of stapled 1×2 lumber, thensurrounding the assembly with a cover which consists of a mattressticking around the sides (to match the mattress) and a light gauze-likefabric on the top/bottom. This gauze-like fabric rips easily and is thesource of frustration for many mattress owners that attempt to movetheir foundation from one room or residence to another. The metal wirestructures do not provide a uniform solid surface on which the mattresscan rest, allowing local deformation of the mattress. To save cost, manymattress manufacturers put in too few metal wire structures, orstructures with wire that is too thin. Manufacturers of high qualityfoundations must attach a price tag that limits the number of customersthey will have. Another problem is that foundations are bulky andnon-compressible and it is expensive to ship them from one place toanother. This applies to over-the-road shipping as well as localdelivery truck shipping. In addition to taking up too much room in anover-the-road semi-truck, a prior art foundation will not be shipped bysuch carvers as UPS because it exceeds their size limits. A mattressfoundation which could be so compact as to ship by UPS, which has a130-inch limit on height plus girth, would save shippers and thusconsumer a lot of money, and enable products to become nationallydistributed which are otherwise limited to being regional. Anotherproblem with the prior art is that the gauze-like fabrics, or evenhigher-quality mattress tickings used by high-quality manufacturers,allow the mattress to slip and slide on the foundation, causing the needfor constant positional adjustment by the accordingly frustrated enduser.

[0616] There thus exists a need for a mattress foundation which ships ina more compact fashion, has exceptional durability, does not allow localor bulk deformation on even heavy mattresses, provides a non-slipmattress interface surface, and achieves all of this at very low cost. Afurther need exists for such a mattress foundation which can be made socompact as to ship via local delivery truck in one or more packages anddoes not require complicated assembly by an end user.

[0617] This embodiment is a mattress foundation comprising a relativelyrigid top and separate or separable sides and/or ends. Theseparate/separable sides and/or ends either easily disassemble from thetop or fold into parallel with the top.

[0618] In one example embodiment, which is shown in FIGS. 65 and 66 andwhich is easily shippable, the foundation is divided into six segments.Each segment has a ¼ inch thick plywood top, under which is stapled agrid of 1×2 lumber on approximately 14-inch centers, with the 1.50″dimension of the (nominal) 1×2 lumber orthogonal to the plane of theplywood. The plywood overlaps the grid of 1×2's by ¼ inch. The totalthickness of this “top” is 1.75″, so six of them can be stacked andshipped via UPS even in a king-size foundation, in which the dimensionsof each top would be approximately 37 inches by 26 inches. In a separatecontainer, the frame is shipped as separate boards in a narrow stack.The frame consists of ¼ inch thick plywood slats (seven, in the case ofthe foundation 6501 of FIG. 65) which are joined by plastic extrudedpieces which slip over slots machined into the slats (well known in thewaterbed art as part of a much different type of foundation used inconjunction with a wooden waterbed). The center three slats are notchedto allow them to all have their top surfaces at the same level. FIG. 66shows the six tops all set into the frame 6601. Attaching the tops tothe frame is not necessary, since the angle-iron bed frame constrainsthe frame, as does each of the six tops, from distorting in the plane ofthe mattress. The mattress weight keeps the tops from coming up out ofthe frame, while the ¼ inch overhang on each top prevents the top fromgoing down through the frame. Thus the foundation is constrained in alldirections and the tops do not need to be attached by mechanical means.To move the foundation from one room or residence to another, one simplylifts out the six tops, removes the plastic connectors, and moves themindependently, then reassembles them in the new room. All is donewithout any tools, and is very simple. The plywood top is continuous, isrigid and made even more rigid by the 1×2 grid, and the bulk stiffnessof the foundation is ensured by the multi-board frame. The top of theplywood can be sprayed or rolled with a pigmented solvated rubber-likethermoplastic elastomer, such as any of the Kraton D elastomers fromShell Chemical mixed with toluene, and the solvent allowed to evaporate.Alternatively, the elastomer can be melted and applied in the moltenstate. The remaining thin layer of rubber-like material creates anon-slip mattress surface, and the pigment hides the plywood. The outerslats of the frame can be covered at the manufacturing stage withupholstery material to match the mattress, and when combined with thepigmented tops create a very aesthetically attractive look. Thedurability of the foundation is assured by the use of durableconstruction materials such as plywood; there are no gauze-like fabricsto be easily ripped or other non-durable materials. The cost issufficiently low to be an attractive feature. The total direct labor andmaterial cost of a queen-sized foundation is expected to be less than US$20.00, which is on par with the cheapest gauze-covered foundations ofthe prior art. The weight of a queen-size foundation in accordance withthis example embodiment is expected to be less than 50 pounds, on parwith other poorer quality foundations.

[0619] Another example embodiment is geared toward shipping inconventional semi-trucks and local delivery trucks. Retail mattresssellers generally would find any assembly undesirable, even the smallamount of assembly described in the above easily shippable embodiment.This alternate example embodiment is illustrated in FIGS. 67a-e. A ¼inch thick plywood top which spans the entire mattress foundation isused, under which is stapled a grid of 1×2 lumber on approximately14-inch centers, with the 1.50″ dimension of the (nominal) 1×2 lumberorthogonal to the plane of the plywood. The plywood is flush with theedge of the grid of 1×2's. ¼ inch thick plywood ends and sides arehinged to the top and fold in as shown in the previous figures. Theoverall assembly is only 2.3 inches thick when folded, so it ships inless than ⅓ the space of a prior art 7-inch thick foundation. FIG. 67eshows the foundations of this example embodiment stacked compactly forshipment. The retailer will drive the still compact foundation to thecustomer's home, unfold the sides and ends in a simple motion, andattach the sides and ends to each other at the four corners. Thisattachment involves only the lining up of the corners and the guiding inof a pre-installed attachment, such as a barbed male-in-femaleattachment which does not come out once installed. Instructions forfabricating this example embodiment are as follows:

[0620] 1. Cut all plywood, 1×2 lumber, fabric, foam, and galvanizedstrips to size.

[0621] 2. Staple (or nail) the width-wise continuous slats flush allaround with the edges of the top plywood. Make sure any width-wise seambetween two pieces of plywood is centered on a slat and that each pieceof plywood is independently fastened to that slat.

[0622] 3. Staple (or nail) the length-wise slats to the width-wise slatsand to the top plywood. Use marking template as needed to ensure thatthe staples through the top plywood are centered on the slats. Make sureany length-wise seam between two pieces of plywood is centered on a slatand that each piece of plywood is independently fastened to that slat.

[0623] 4. Using four screws per strip, screw one side of the 9″galvanized strips to the end and side panels. For twin size foundations,there will be two on each end panel and three on each side panel. Forall other sizes, there will be three on each end panel and three on eachside panel. They should be evenly spaced apart. Note that on the endpanels, the outside strips should be 5.5″ from the panel ends (so as notto interfere with the unfolding of the side panels), whereas for theside panels, the outside strips should be flush with the panel ends.

[0624] 5. Place the foam (without adhesive) on a plywood side panel.Place the fabric over the foam and wrap around to the back underreasonable tension. It will overlap {fraction (1/2)} inch on all fouredges onto the back. Staple the fabric under tension to the back on allfour edges. Note: These should be normal wood staples, not the kindcoated with hot-melt adhesive that will be used for the top-to-slatstapling. Repeat for the other side panel and the two end panels.

[0625] 6. Attach a plywood spacer to the 1×2's in every place wherethere is a galvanized strip on the corresponding end panel.

[0626] 7. Keeping the side and end panels parallel to (but not evenwith) the top plywood, attach the side and end panels to the perimeter1×2's by screwing on the galvanized strips. Again use four screws perstrip.

[0627] 8. Fold in the side panels.

[0628] Another example embodiment is illustrated in FIGS. 68a and 68 b.This foundation 6801 consists of a {fraction (1/4)} inch thick plywoodtop 6802 but in this case has no 1×2 stiffener grid as in the previoustwo examples. It has a fold-down side as in the previous example. Thefold-down ends of example 2 exist, and are accompanied by a series ofinternal panels similar to the ends except not upholstered. Theseinterior panels act to stiffen the plywood top in lieu of the 1×2 grid.The end and interior panels fold down an orthogonal angle to the top.The side panels do so also, and have slots machined in their sides toreceive the edges of the side and interior panels. This embodimentenjoys similar cost and weight and performance advantages of theprevious examples, with similarly low assembly-on-site labor. However,this embodiment ships even more compactly, with a folded width of lessthan 1 inch. Thus more than seven foundations can be shipped in thespace occupied by one prior art foundation.

[0629] Another example embodiment utilizes a plywood/grid top as inanother example above but without the fold-down sides and ends. The topis built to have a ¼ inch overlap of the plywood from the 1×2 grid. Thetop is set into a border frame, consisting of integral sides and ends.The top may be attached or not as example. The sides and ends are angledfrom vertical slightly to allow stacking of the border frames. If thetops are attached, the foundations can still stack compactly. If theframes are unattached, it may be advantageous to stack the border framesand the tops separately for maximum overall compaction. The border framecan be made of wood or wood composites. It can also be made by formingplastic sheet into a frame, such as ⅛-inch thick polyethylene.

[0630] In the examples above, the top of the plywood can be sprayed witha pigmented solvated rubber-like thermoplastic to create a non-slipmattress surface, with the pigment hiding the plywood.

[0631] The devices are not limited to any particular material orspecific configuration so long as it comprises a relatively rigid topand separate/separable sides which either easily assemble/disassemblefrom the top or fold into parallel with the top. The materials can beany economical structurally sound material, including but not limited toplywood, oriented strand board (OSB), chipboard, pressboard, plastic,metal, masonite, or composite materials. The top is example to becontinuous but can be perforated or discontinuous so long as it providesthe needed overall rigidity and does not have gaps so large as to allowthe mattress to have localized deformation. The size of the allowed gapsdepends on the floppiness of the mattress; e.g., a firm innerspringmattress can sit atop larger gaps than a foam mattress.

[0632] The mattress foundations hereof, as illustrated by but notlimited to the examples shown, are different from and superior to theprior art in several ways:

[0633] 1. Unlike prior art foundations for conventional mattresses, myfoundations ship more compactly, saving considerable expense in shippingand expanding the market area in which a mattress manufacturer cancompete.

[0634] 2. Unlike prior art foundations for conventional mattresses, myfoundations are more rigid and thus allow less deformation both in anoverall and a local sense.

[0635] 3. Unlike prior art foundations for conventional mattresses whichare inexpensive to produce, my foundations are more durable because allof the materials of construction are durable (no thin fabrics, etc.).

[0636] 4. Unlike prior art foundations for conventional mattresses thatuse quality fabrics and are thus durable and that use sufficient metalspacers to effect high rigidity, my foundations are inexpensive toproduce because I use the rigidity and durability of inexpensivematerials such as plywood rather than labor-intensive and costly heavysteel wire structures bridged with quality fabrics.

[0637] 5. Unlike prior art foundations for conventional mattresses,devices herein allow for foundations which collapse to the point thatthey can be shipped local delivery truck, and even these versions do notrequire labor intensive or tool intensive assembly by the end user.

[0638] 6. Unlike all known prior art mattress foundations, myfoundations have an anti-slip option.

[0639] The main feature hereof is separate/separable sides/ends inconjunction with a relatively rigid top or tops which enable(s) compactshipping. Some of the additional features include but are not limitedto:

[0640] a. The optional use of ductile thin metal as hinges, usablebecause the hinges will be actuated very few times and so metal fatiguefailure does not come into play.

[0641] b. The optional pre-application of fabric and other upholsterymaterials (such as foam) to the individual sides and/or ends of afoundation. In prior art foundations, such upholstery is only applied tothe assembled foundation, which prevents some of the features.

[0642] c. The optional use of a solvated elastomer or melted elastomerto facilitate the spray or roller application of the elastomer to afoundation top.

[0643] d. The optional use in general of a non-skid top in a mattressfoundation.

[0644] e. In a foundation, the optional use of a grid (1×2's in theexamples) firmly attached to a relatively thin skin (¼-inch plywood inthe examples) to provide an overall very stiff top and/or side and/orend structure.

[0645] f. The use of a barbed fastener or other low-labor fasteners tolocate one foundation component relative to another.

[0646] 4. Podalic Pads

[0647] Elastomeric or viscoelastomeric podalic pads using materials andor structures described herein can be created.

[0648] 5. Elastomer Chews

[0649] These devices includes an elastomeric or viscoelastomeric chews.The material may be shaped for chewing and may be impregnated with asubstances that slowly releases into the mouth while being chewed, suchas medications, drugs, flavors, sweeteners, herbs, vitamins, minerals,dietary supplements, homeopathic remedies, and any other substance thatis desired to be slowly released into the mouth. Most rubbers andelastomers are non-polar and have a definable solubility factor. Mostsubstances to be released into the mouth are polar and have a solubilityfactor different from elastomers. When blended with an elastomer, thesubstance to be released does not chemically bond with the elastomer, soduring chewing the substance to be released immediately separates fromthe elastomer. But when the materials are used, a polar bond is formedbetween the substance to be released and the elastomer, so that thesubstance to be released works out of the elastomer matrix slowly duringchewing. Chewing the elastomer chew does not fatigue the jaw and mouthof the chewer as chewing gum does because the elastomer rebounds to itsoriginal shape during chewing rather than sticking to the teeth andcreating suction as chewing gum does.

[0650] Referring to FIGS. 69a, 69 b and 69 c, a top view, front view andend view (respectively) of an elastomer chew 6901 are shown.

[0651] 6. Cushions that Include Hollow Column Gel and a SecondCushioning Element

[0652] Referring to FIGS. 70-85, embodiments which include both a hollowcolumn gel as described herein and at least a second cushioning elementare shown. The advantages of buckling columns are already describedherein. Combining buckling column cushions with another cushioningelement and at least 30% void space in stacked sequence is veryadvantageous. This applies to many products including beds, mattressing,operating table pads, stretcher cushions, sofas, chairs, wheelchair seatcushions, vehicle seats, bicycle seats, forklift seats, truck seats, carseats, lawnmower seats, motorcycle seats, tractor seats, boat seats,plane seats, train seat and others.

[0653]FIG. 70 depicts a 2″ high hollow column gel elastomer 7001 with 1″square columns and 0.125″ wall thickness topped with a quilted fiber top7002 as is commonly found in the mattressing art. This allows the userof the cushion to enjoy breathability between his body and the gel, andto avoid the high friction of contact with the gel. Further, since thegel will not touch the user's skin, the user will not feel cold ontouching the cushion,

[0654]FIG. 71 depicts a first hollow column gel cushioning element 7101,a second hollow column gel cushioning element 7102 and a quilted fibertop 7103 in stacked sequence. The firmness of the hollow column gelcushioning elements may be varied to increase the surface area of theuser being cushioned.

[0655]FIG. 72 depicts a tall gel column 7002 topped with a quilted top7003 that includes fiber 7001 and foam 7004. The foam creates extrathickness and a bridging effect over the hollow columns, allowing largecolumns to be used, such as 6″ tall, with 1.8″ square holes and 0.10″wall thickness. Greater hole size reduces weight and cost of the hollowcolumn gel.

[0656]FIG. 73 depicts a first hollow column gel 7301 that is 6″ high andhas 1.8″ square holes and 0.10∝ wall thickness. A second hollow columngel 7302 is stacked thereon using 2″ hollow columns with 1″ square holesand 0.125″ wall thickness. That is topped with a quilted top with fiber7303. The short columns provide a plush bridging effect for thedeep-sinking tall columns.

[0657]FIG. 74 depicts two short hollow column gel elements 7401 and 7402atop a tall hollow column gel element 7403 with large holes, the entirecombination topped with a quilted top 7404. Durometers of the cushioningelements may be varied.

[0658]FIG. 75 depicts a short cushioning element 7501 atop a thick layerof polyurethane foam 7502, the entire assembly being topped with aquilted top 7503.

[0659]FIG. 76 depicts a thick layer of polyurethane foam 7601 on top ofwhich is found a first 7602 and a second 7603 short hollow column gelcushioning element, followed by a quilted top 7604. This configurationhas good side stability.

[0660]FIG. 77 depicts a slab of high grade visco foam 7701 on top ofwhich is found a short hollow column gel element 7702 and a quilted top.Visco foam is also called gel foam and Tfoam. Visco-form easily forms tothe shape of the object being cushioned, while still providing sidestability.

[0661]FIG. 78 depicts a prior art spring unit 7801 which is well known,followed by a short unit of hollow column gel 7802 and a quilted top7803. The gel columns in this embodiment overcome the peak pressureproblems of spring units.

[0662]FIG. 79 depicts a spring unit 7901 topped with a first 7902 and asecond 7903 hollow column gel cushion and a quilted top 7904.

[0663]FIG. 80 depicts use of a shallow spring unit 8001 topped with athick hollow column gel unit 8002 using large columns, and the top layer8003 being a quilted top with foam 8004 for bridging across the largecolumns.

[0664]FIG. 81 depicts a slab of latex foam 8101 topped with a shorthollow column gel unit 8102 and a quilted top 8103.

[0665]FIG. 82 depicts another embodiment with a base of tall hollowcolumn gel with large columns 8201, followed by a latex foam rubbertopper 8202 and a quilted top 18 8203.

[0666]FIG. 83 depicts a tall column hollow column gel element 8301followed by a layer of latex foam 8302 and a quilted top 8303.

[0667]FIG. 84 depicts a tall hollow column gel element 8401 followed bya layer of polyurethane foam 8402 and a quilted top 8403.

[0668]FIG. 85 depicts a tall unit of hollow column gel 8501 topped witha layer of pillow soft polyurethane foam 8502 and a quilted top 8503.

[0669] 7. Method for Extruding Large Internally Complex DiscontinuousStructures

[0670] A method for extruding cushioning shapes is provided below. Themethod permits the extrusion of polymeric parts of complex geometrywhich are short in cut-off length but of large dimension in one or moredimensions transverse to the material flow.

[0671] A significant problem in extrusion is differential coolingbetween the exterior and interior of the part causing shrinkage and partdeformation. Another problem is that air pressure differences in thepart interior causes part blow up or collapse. The larger the extrudedpart, the greater these problems are. When hollow column gel parts aremade, the parts will preferably be very large, such as at least 45inches square. In the prior art it was not considered possible tomanufacture large, low-durometer gel products, such as the hollow columngel cushioning elements, by extrusion, particularly if the part to beextruded is floppy and does not stand under its own weight.

[0672] Referring to FIG. 86, a novel extrusion die is depicted. The dieis useful in extruding a king sized mattress core in a single piece, theoverall dimensions of which are 76 inches by 79.5 inches by 6 inchesthick. Internally, the example mattress core would include hollow squarecolumns of about 2 inches by 2 inches with a wall thickness of about0.10 inches. The gelatinous elastomer or viscoelastomer to be used is asdescribed elsewhere herein, but is low durometer and floppy.

[0673] The extrusion die 8601 is constructed as follows. Note that thefigure depicts only a portion of the whole die, for simplicity. A steelbase plate 8602 of about 80×84 inches is machined flat to a thickness ofabout 1 inch. Aluminum cores 8603 are provided attached to the baseplate. The aluminum cores are machined to about 1.95″×1.95″×1.5″. Thecores are attached to the base plate with a spacing of 0.10″ in order tocreate hollow column gel with 0.10″ wall thickness. As molten elastomerfloods through the space between the cores, the desired cushioningelement shape is formed. A cap plate 8604 is attached to the base plate,of the same dimension as the base plate. Runners are machined into thebase plate and the cap to permit molten elastomer to be forcedtherethrough by a press of sufficient strength. Small holes 8605 aredrilled between the runners and the spaces 8606 or runways between thecores 8603 to permit molten elastomer to flow from the runners throughthe holes and through the runways to form a cushioning element. Themolten material can flow through the runners much more easily thanthrough the small drilled holes, resulting in reasonably equalizedpressure as the molten material moves through the runways 8605. Moltenmaterial enters the die 8601 at an input and exits the die 8601 at anoutput 8608. As the material exits the die at the output, it isimmediately cooled in a water bath 8609 so that from the water bath exit8610 a frozen finished part is produced. The use of a water bathstabilizes the part shape. As material exits the die and enters thewater bath, at an appropriate dimension it will be cut according to aprior art cutting method. Air pressure is not needed within the partbecause the water bath provides even cooling and part shape stability.In the water bath, there is no tendency of gravity to cause sidewallcollapse of the part. The specific gravity of the example elastomer is0.88, near enough the specific gravity of water (1.0) such that buoyancywill not deform the part.

[0674] It is example that the water bath be at or near boiling. This isbecause as the water inside of cells of the hollow column gel heats upfrom the cooling process, it would create a temperature differentialwith water outside of the cells which does not heat up as much. Transferof heat from the elastomer to the water causes steam. Vent holes in thecores and plates are provided to accommodate release of this steam.

[0675] Although the example coolant is water, other flowable coolingmediums could be used, such as air, glycerin, propylene glycol, oil,plastic beads, hydraulic fluid, heat transfer fluid, and other materialsthat do not deform the elastomer part. If stiff parts are being made,air may be an appropriate coolant. In some instances, such as with a lowspecific gravity part, it is desired to cut the part off from the diebefore it enters the water to avoid deformation due to buoyancy.

[0676] The extrusion example herein is downward extrusion into water,but upward extrusion is also contemplated. In such a case, the coolantwould be in direct contact with the die face and the die face would bein a tank of coolant. Parts would tend to buoy up in the coolant as theyexit the die.

[0677] 8. Gel-Coated Fabrics

[0678] Another embodiment is to coat fabrics etc. with a highlyplasticized A-B-A triblock co-polymer of the SEPS, SEEPS or SEEEPSvariety (styrene-[ethylene-ethylene propylene]-styrene orstyrene-[ethylene-ethylene-ethylene-propylene]-styrene). The EEEPmid-block is preferably of very high molecular weight, such that thesolution viscosity is so high as to be essentially a solid when at 20%solids in toluene @ 25 degrees C. Preferably, the plasticizer is a whiteparaffinic mineral oil such as Witco LP-200. Preferably, anfluorochemical such as Dupont Zonyl BA-N is added to slow or completelyprevent the wicking out of the plasticizer. My most example SEEEPStri-block co-polymer is Septon 4055 by Kuraray of Japan. Septon 4055 isa solid elastomeric gel when combined with toluene at 20% solids @ 25degrees C., and not a liquid at all, so that solution viscosity is ameaningless term for Septon 4055. Septon 4055 exhibits less plasticizerwicking than other copolymers, and produces a stronger and more durablegel.

[0679] The most example plasticizer to copolymer ratio for fabriccoatings is in the range of 4-to-1 to 2-to-1. More or less plasticizeris allowable within the scope. More plasticizer is not example for mostapplications because the tackiness of the gel is higher as plasticizercontent increases. Less plasticizer is not example for most applicationsbecause the lower the plasticizer content, the more effect on supplenesswill be noticed.

[0680] The need exists for an additive which substantially reduces andpreferably completes stops wicking of the plasticizer. The fabriccoating thus preferably includes an additive such as is fully describedabove. As stated above, my most example additive is Dupont'sfluorochemical alcohol Zonyl BA-N, added at 0.05% to 0.75%, typically0.20% to 0.35%, of the total gel weight. Other fluorochemicals,particularly fluorochemical alcohols and surfactants, are also exampleanti-wicking additives in the coating.

[0681] The results of applying my example gel coating to a fabric areexcellent. Because the durometer is so low (Shore A10 at the highest,but usually well below the Shore A scale altogether), the suppleness ofthe fabric is virtually unaffected. Since it can stretch to as much astwenty times its original length without permanent set, and since it isof such low durometer, the stretchiness of fabrics such as Dupont'sLycra is virtually unaffected. It is essentially water proof. It has alow degree of air permeability, so that in very thin coatings it allowssome breathing of air and vapors, and with somewhat thicker coatings isfor all practical purposes gas impermeable. It is very lightweight, witha density of 0.86 to 0.88 grams per cubic centimeter (as a comparison,silicone gel is about 0.98, polyurethane film is about 1.25, and rubberdensity varies depending on fillers used but is generally more than thatof my example gel. It is relatively inexpensive, costing about 80% asmuch as Mr. Chen's example gels, 50% as much as neoprene, and 30% asmuch as polyurethane film. It does not wick plasticizer at all at roomtemperature when placed next to photocopier paper.

[0682] The example gel can be applied to fabrics in a variety of ways.One example method is to solvate the gel ingredients in toluene oranother organic solvent, using enough toluene to produce the viscositydesired. The solvated gel is coated onto the fabric by coating meanswell known in the art, such as a roller and doctor blade, then thetoluene is evaporated off, usually with heat, and usually recovered soas to prevent air pollution. Another example method is to heat and shearthe gel ingredients at sufficient temperature (usually 350 to 400degrees F. is sufficient) that a thoroughly molten and mixed fluid isobtained. The molten fluid is then coated onto the fabric with similarmeans as in the solvated case, and the molten gel is allowed to cool andsolidify. Other means are also feasible, including but not limited toextruding the molten gel into a film, cooling it, then heat-laminatingthe film to the fabric. Other methods might include hot molten gel sprayand solvated gel spray.

[0683] This disclosure is not to be limited by the foregoing preferencesand examples. Any type of fabric or other pliable, porous material(including but not limited to paper and foam) coated with or laminatedto the range of gels described above or coated with or laminated to anyplasticized elastomer containing anti-wicking additives orbleed-reducing additives as described above also falls within the scope.Any method of applying the coating or laminated layer is acceptable.

[0684] 9. Summary of Some Alternative Embodiments

[0685] Referring to FIGS. 87-97, various alternative embodiments aredepicted. Each of these is a cushioning device which may be incorporatedinto any type of cushion desired.

[0686]FIG. 87 depicts a base of a non-skid (high friction) fabric 8701on which a cushioning element 8702 is found topped by a pearlized chintzquilt with foam and fiber 8703. The cushioning element 8702 has bucklingfoam rails.

[0687]FIG. 88 depicts a base of non-skid fabric 8801 under a bucklingfoam rail cushioning element 8802 and topped with a pearlized chintzpillow top with foam, convoluted foam and fiber.

[0688]FIG. 89 depicts a base of Belgian damask tick 8901 on which acushioning element 8902 of foam buckling rails is place. On top of thatis found a layer of supersoft latex foam 8903 followed by a top ofBelgian damask quilt with foam and fiber 8904.

[0689]FIG. 90 depicts a base of Belgian damask tick 9001 which has abuckling rail cushioning element 9002 on top of it with buckling railsin only one direction, followed by a buckling rail cushioning element9003 that has buckling roam rails in two directions, followed by a layerof supersoft latex foam 9004 and a top of Belgian damask quilt with foamand fiber.

[0690]FIG. 91 depicts a base of Belgian damask tick 9101 on which is acushioning element 9102 with buckling roam rails in two directions, asecond cushioning element 9103 with buckling foam latex rails in twodirections, a layer of supersoft latex foam 9104 and a top of Belgiandamask tick with supersoft fiber.

[0691]FIG. 92 depicts a base of Belgian damask tick 9201 on top of whichis a cushioning element 9202 of hollow column gel surrounded byborder-stiffening foam and a foam base, and a top 9203 of Belgian damaskquilt with foam and fiber.

[0692]FIG. 93 depicts a base 9301 of Belgian damask tick followed by acushioning element 9302 of gel hollow columns bordered by foam and witha foam base, followed by two-dimension buckling rail foam 9303 and a topof Belgian damask quilt with foam and fiber 9304.

[0693]FIG. 94 depicts a base of non-skid fabric 9401 followed bymattress inner springs 9402, then by buckling rail foam with rails intwo directions 9403 and a top of pearlized chintz quilt with foam andfiber.

[0694]FIG. 95 depicts a base of Belgian damask tick 9501 under metalmattress inner springs 9502 followed by a cushioning element 9503 withfoam latex buckling rails in two directions, and a top 9504 of Belgiandamask quilt with supersoft fiber.

[0695]FIG. 96 depicts a cushioning element 9601 of buckling foam railsin two directions with foam borders, a foam base and a foam top, asecond unit of 2 inches of memory foam 9602 and a stretch knit cover9603.

[0696]FIG. 97 depicts a cushioning element 9701 of buckling latex foamrails in two directions, with a layer 9702 of latex foam on top followedby a stretch knit cover 9704.

[0697] The reader should note that any other manufacturing method may beused which results in a cushioning element having the generalconfiguration of or achieving the object hereof. Such other methods mayinclude but are not limited to rotational molding of a cushioning mediasuch as a hot liquid gel, and vacuum forming of sheets of a cushioningmedia such as gel.

[0698] While the present devices, methods and materials have beendescribed and illustrated in conjunction with a number of specificembodiments, those skilled in the art will appreciate that variationsand modifications may be made without departing from the principles asherein illustrated, described, and claimed.

[0699] The present devices, materials and methods may be embodied inother specific forms without departing from its spirit or essentialcharacteristics. The described embodiments are to be considered in allrespects as only illustrative, and not restrictive. The scope of theinvention is, therefore, indicated by the appended claims, rather thanby the foregoing description. All changes which come within the meaningand range of equivalency of the claims are to be embraced within theirscope.

What is claimed is:
 1. A yieldable cushioning element that includesfoam, the cushioning element comprising: foam formed to have a top, abottom, and an outer periphery, said foam being compressible so that itwill deform under the compressive force of a cushioned object, aplurality of buckling members formed in said foam, each of said bucklingmembers having a longitudinal axis along its length, and each of saidbuckling members having two ends; wherein the cushioning element isadapted to have a cushioned object placed in contact with said top;wherein each of said buckling member ends is positioned at two differentpoints of said buckling member axis; wherein at least one of saidbuckling members is positioned within said foam such that said bucklingmember axis is positioned generally parallel to the direction of acompressive force exerted on the cushioning element by a cushionedobject in contact with said foam; and wherein at least one of saidbuckling members is capable of buckling beneath a protuberance that islocated on the cushioned object.
 2. A yieldable cushioning element asrecited in claim 1, wherein at least one other of said buckling membersis positioned such that said buckling member axis is not parallel to thedirection of a compressive force exerted on the cushioning element bythe cushioned object in contact with said foam.
 3. A yieldablecushioning element as recited in claim 1, wherein said foam is open-cellpolyurethane.
 4. A yieldable cushioning element as recited in claim 1,wherein said foam has an ILD of about 50 and a density of about 2.8pounds per square inch.
 5. A yieldable cushioning element as recited inclaim 1, wherein a cross section of one of said buckling members takenorthogonal to said longitudinal axis of said buckling member has a shapeselected from the group consisting of triangular, square, rectangular,pentagonal, heptagonal, octagonal, round, oval, and n-sided polygonalwhere n is an integer.
 6. A yieldable cushioning element as recited inclaim 1, wherein said foam has shape memory so that when a cushionedobject is removed from contact with the foam, the foam has a tendency toreturn to a shape that approximates the shape of the cushioning elementbefore the cushioning element and the cushioned object came into contactwith each other.
 7. A yieldable cushioning element as recited in claim1, wherein at least one of said buckling members has a greatermeasurement orthogonal to said buckling member axis at a first point onsaid buckling member axis than at a second point on said buckling memberaxis.
 8. A yieldable cushioning element as recited in claim 1, whereinat least one of said buckling members is tapered between the first ofsaid buckling member ends and the second of said buckling member ends.9. A yieldable cushioning element as recited in claim 1, wherein atleast one of said buckling members is stepped between the first of saidbuckling member ends and the second of said buckling member ends.
 10. Acushioning element as recited in claim 1, wherein at least one of saidbuckling members has a firmness protrusion located at one of saidbuckling member ends, said firmness protrusion being adapted to providesupport within said buckling member when said buckling member bucklesunder a compressive force so that the cushioning element can readilyyield in the vicinity of said buckling member under a cushioned objectuntil the cushioned object begins to compress said firmness protrusion,whereupon said firmness protrusion retards further movement of thecushioned object into the cushioning element.
 11. A yieldable cushioningelement as recited in claim 1, and further comprising a cover.
 12. Amethod for making a yieldable cushioning element comprising the stepsof: obtaining a bun of foam that has a length, a width, a height, afirst face defined by the surface area of said length and said heightdimensions, and a second face defined by the surface area of said widthand said height dimensions, making first cuts along said length uponsaid first face completely through said width, making second cuts alongsaid length upon said first face completely through said width, wherethe order of said cuts from a top of said height to a bottom of saidheight starts with said second cut near said top, then said first cut,then said second cut, repeating until reaching said bottom where thelast cut before said bottom is a said second cut, and where said firstcuts and said second cuts are evenly spaced from said top to saidbottom, where the distance between said top and said first cut mostproximal to said top is a first cut spacing, the distance between theinterior said first cuts is equal to said first cut spacing, thedistance between said bottom and said first cut most proximal to saidbottom is equal to said first cut spacing, making third cuts centered onsaid second cuts where said third cuts extend for a portion of saidheight less than said first cut spacing, for a portion of said length,and through said width, where said third cuts form a closed geometricshape on said first face and are repeated along said length, and makingfourth cuts on said second face through said length, centered on saidsecond cuts where said fourth cuts have similar dimensions to said thirdcuts but form a closed geometric shape on said second face and arerepeated along said width, and separating said foam along said firstcuts revealing cushion segments, separating said cushion segments alongsaid second cuts revealing top half cushion segments, bottom halfcushion segments and half buckling members created by said third cutsand said fourth cuts, removing disconnected pieces of foam, and applyingadhesive to exposed ends of said half buckling members, aligning andcontacting said exposed ends of said half buckling members of said tophalf cushion segments with said exposed ends of said half bucklingmembers of said bottom half cushion segments.
 13. A method for making ayieldable cushioning element comprising the steps of: obtaining a bun offoam that has a length, a width, a height, a first face defined by thesurface area of said length and said height dimensions, and a secondface defined by the surface area of said width and said heightdimensions, making first cuts on said first face along said length andthrough said width where said first cuts are evenly spaced from a top ofsaid height to a bottom of said height, making second cuts on said firstface where there is one said second cut between said top and the saidfirst cut most proximal to said top, where there is one said second cutbetween each interior said first cuts, and where there is one saidsecond cut between said bottom and the said first cut most proximal tosaid bottom, where said second cuts run along said length and throughsaid width, where said second cuts create a repeating pattern comprisedof n interlocking units, where the repeating pattern is comprised of afirst interlocking unit oriented one direction between said top and saidbottom and one dimension of said first interlocking unit is parallelwith the axis through said height from said top to said bottom, a secondinterlocking unit contiguous with said first interlocking unit that issimilar to said first interlocking unit but oriented 180 degrees opposedto said first interlocking unit, a third interlocking unit contiguouswith said second interlocking unit that is similar to said secondinterlocking unit but oriented 180 degrees opposed to said secondinterlocking unit and 0 degrees opposed to said first interlocking unit,and where said repeating pattern repeats through n interlocking unitswith all odd numbered interlocking units oriented in the direction ofsaid first interlocking unit and all even numbered interlocking unitsoriented in the direction of said second interlocking unit, andseparating foam along said first cuts revealing cushion segments,separating cushion segments along said second cut revealing top halfcushion segments, bottom half cushion segments and half buckling memberscreated by said second cuts, removing disconnected pieces of foam,applying adhesive to exposed ends of said half buckling members, andaligning and contacting said exposed ends of half buckling members. 14.A method for making a yieldable cushioning element comprising the stepsof: obtaining a bun of foam that has a length, a width, a height, afirst face defined by the surface area of said length and said heightdimensions, and a second face defined by the surface area of said widthand said height dimensions, making first cuts along said length uponsaid first face completely through said width, making second cuts alongsaid length upon said first face completely through said width, wherethe order of said cuts from a top of said height to a bottom of saidheight starts with said second cut near said top, then said first cut,then said second cut, repeating until reaching said bottom where thelast cut before said bottom is a said second cut, and where said firstcuts and said second cuts are evenly spaced from said top to saidbottom, where the distance between said top and said first cut mostproximal to said top is a first cut spacing, the distance between theinterior said first cuts is equal to said first cut spacing, thedistance between said bottom and said first cut most proximal to saidbottom is equal to said first cut spacing, making third cuts centered onsaid second cuts where said third cuts extend for a portion of saidheight less than said first cut spacing, for a portion of said, andthrough said width, where said third cuts form a closed geometric shapeon said first face and are repeated along said length, making fourthcuts on said second face through said length, centered on said secondcuts where said fourth cuts have similar dimensions to said third cutsbut form a closed geometric shape on said second face and are repeatedalong said width, separating foam along said first cuts revealingcushion segments, separating said cushion segments along said secondcuts revealing top half cushion segments and bottom half cushionsegments and half buckling members created by said third cuts and saidfourth cuts, removing disconnected pieces of foam, and applying adhesiveto exposed ends of said half buckling members, aligning and contactingsaid exposed ends of said half buckling members of said top half cushionsegments with said exposed ends of said half buckling members of saidbottom half cushion segments.
 15. A method as recited in claim 14,wherein at least one other of said buckling members is positioned withinsaid foam such that it is not parallel to the direction of a compressiveforce exerted on the cushioning element by a cushioned object in contactwith said foam.
 16. A method as recited in claim 14, wherein said foamis open-cell polyethylene based polyurethane.
 17. A method as recited inclaim 14, wherein said foam has an ILD of about 50 and a density ofabout 2.8 pounds per square inch.
 18. A method as recited in claim 14,wherein said foam has shape memory so that when a cushioned object isremoved from contact with the foam, the foam has a tendency to return toa shape that approximates the shape of the cushioning element before thecushioning element and the cushioned object came into contact with eachother.
 19. A method as recited in claim 14 where said third cuts andsaid fourth cuts form rectangular patterns on said first face and saidsecond face respectively.
 20. A method as recited in claim 14, whereinat least one of said buckling members has a firmness protrusion locatedat one of said buckling member ends, said firmness protrusion beingadapted to provide support within said buckling member when saidbuckling member buckles under a compressive force so that the cushioningelement can readily yield in the vicinity of said buckling member undera cushioned object until the cushioned object begins to compress saidfirmness protrusion, whereupon said firmness protrusion retards furthermovement of the cushioned object into the cushioning element.
 21. Amethod as recited in claim 14, wherein said bun of foam has a height ofat least 30 inches, and a length of at least 80 inches and a width of atleast 60 inches.
 22. A method as recited in claim 14, wherein said firstcuts, said second cuts, said third cuts and said fourth cuts are madewith a CNC reciprocal saw.
 23. A method as recited in claim 14, whereinsaid third cuts are evenly spaced along said length, and said fourthcuts are evenly spaced along said width.
 24. A method as recited inclaim 14, and further comprising forming a cover on said cushion.
 25. Amethod for making a yieldable cushioning element having bucklingmembers, the method comprising the steps of: obtaining a bun of foamthat has a length, a width, a height, a first face defined by thesurface area of said length and said height dimensions, and a secondface defined by the surface area of said width and said heightdimensions, making first cuts on said first face along said length andthrough said width where said first cuts are evenly spaced from a top ofsaid height to a bottom of said height, making second cuts on said firstface where there is one said second cut between said top and the saidfirst cut most proximal to said top, where there is one said second cutbetween each interior said first cuts, and where there is one saidsecond cut between said bottom and the said first cut most proximal tosaid bottom, where said second cuts run along said length and throughsaid width, where said second cuts create a repeating pattern comprisedof n interlocking units, where the repeating pattern is comprised of afirst interlocking unit oriented one direction between said top and saidbottom and one dimension of said first interlocking unit is parallelwith the axis through said height from said top to said bottom, a secondinterlocking unit contiguous with said first interlocking unit that issimilar to said first interlocking unit but oriented 180 degrees opposedto said first interlocking unit, a third interlocking unit contiguouswith said second interlocking unit that is similar to said secondinterlocking unit but oriented 180 degrees opposed to said secondinterlocking unit and 0 degrees opposed to said first interlocking unit,and where said repeating pattern repeats through n interlocking unitswith all odd numbered interlocking units oriented in the direction ofsaid first interlocking unit and all even numbered interlocking unitsoriented in the direction of said second interlocking unit, andseparating said foam along said first cuts revealing cushion segments,separating cushion segments along said second cuts revealing top halfcushion segments, bottom half cushion segments and half buckling memberscreated by said second cuts, removing disconnected pieces of foam,applying adhesive to exposed ends of said half buckling members, andaligning and contacting said exposed ends of half buckling members. 26.A method for making a yieldable cushioning element as recited in claim25, wherein at least one other of said buckling members is not parallelto the direction of a compressive force exerted on the cushioningelement by a cushioned object in contact with said foam.
 27. A methodfor making yieldable cushioning element as recited in claim 25, whereinsaid foam is open-cell polyethylene based polyurethane.
 28. A method formaking a yieldable cushioning element as recited in claim 25, whereinsaid foam has an ILD of 50 and a density of 2.8 pounds per square inch.29. A method for making a yieldable cushioning element as recited inclaim 25, wherein said foam has shape memory so that when a cushionedobject is removed from contact with the foam, the foam has a tendency toreturn to a shape that approximates the shape of the cushioning elementbefore the cushioning element and the cushioned object came into contactwith each other.
 30. A method for making a yieldable cushioning elementas recited in claim 25 where said third cuts and said fourth cuts formrectangular patterns on said first face and said second facerespectively.
 31. A method for making a cushioning element as recited inclaim 25, wherein at least one of said buckling members has a firmnessprotrusion located at one of said buckling member ends, said firmnessprotrusion being adapted to provide support within said buckling memberwhen said buckling member buckles under a compressive force so that thecushioning element can readily yield in the vicinity of said bucklingmember under a cushioned object until the cushioned object begins tocompress said firmness protrusion, whereupon said firmness protrusionretards further movement of the cushioned object into the cushioningelement.
 32. A method for making a yieldable cushioning element asrecited in claim 25, wherein said bun of foam has dimensions of saidheight equal to 30 inches, said length equal to 80 inches and said widthequal to 60 inches.
 33. A method for making a yieldable cushioningelement as recited in claim 25, wherein said first cuts and said secondcuts are made with a CNC reciprocal saw.
 34. A method for making ayieldable cushioning element as recited in claim 25, wherein each ofsaid interlocking units have a uniform dimensions along said height andsaid length.
 35. A yieldable cushioning element that includes foam, thecushioning element comprising: foam formed to have a top, a bottom, andan outer periphery, said foam being compressible so that it will deformunder the compressive force of a cushioned object, a plurality of foambuckling members formed in said foam, each of said buckling membershaving a longitudinal axis along its length, and each of said bucklingmembers a top end and a bottom end; at least one of said ends of saidfoam buckling members being formed integral with one of said foam top orsaid foam bottom, wherein the cushioning element is adapted to have acushioned object placed in contact with said top; wherein each of saidbuckling member ends is positioned at two different points of saidbuckling member axis; wherein at least one of said buckling members ispositioned within said foam such that said buckling member axis ispositioned generally parallel to the direction of a compressive forceexerted on the cushioning element by a cushioned object in contact withsaid foam; and wherein at least one of said buckling members is capableof buckling beneath a protuberance that is located on the cushionedobject.
 36. A device as recited in claim 1 or 35 manufacturing accordingto a casting technique utilizing rise in place foam.